Soil Survey of the San Miguel Area, Colorado...San Miguel Area, Colorado Parts of Dolores, Montrose, and San Miguel Counties United States Department of Agriculture Natural Resources

In cooperation withColorado AgriculturalExperiment Station

Soil Survey ofSan Miguel Area,ColoradoParts of Dolores, Montrose, andSan Miguel Counties

United StatesDepartment ofAgriculture

NaturalResourcesConservationService

United StatesDepartment ofthe Interior

Bureau of LandManagement

Detailed Soil Maps

The detailed soil maps follow the general information about the survey area. These maps can be useful in planningthe use and management of small areas.

To find information about your area of interest, locate that area on the Index toMap Sheets, which precedes the soil maps. Note the number of the mapsheet and turn to that sheet.

Locate your area of interest on the map sheet. Note the mapunits symbols that are in thatarea. Turn to the Contents, whichlists the map units by symbol andname and shows the page whereeach map unit is described.

The Contents shows which tablehas data on a specific land usefor each detailed soil map unit.Also see the Contents forsections of this publication thatmay address your specific needs.

A State Soil Geographic DataBase (STATSGO) is available forthis survey area. This data baseconsists of a soils map at a scaleof 1 to 250,000 and descriptionsof groups of associated soils. Itreplaces the general soil mappublished in older soil surveys.The map and the data base canbe used for multicounty planning,and map output can be tailored for a specific use. More information about the STATSGO for this survey area, or forany portion of Colorado, is available at the Colorado State Office of the Natural Resources Conservation Service.

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How to Use This Soil Survey

http://www.co.nrcs.usda.gov

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This soil survey is a publication of the National Cooperative Soil Survey, a joint effortof the United States Department of Agriculture and other Federal agencies, Stateagencies including the Agricultural Experiment Stations, and local agencies. The NaturalResources Conservation Service (formerly the Soil Conservation Service) hasleadership for the Federal part of the National Cooperative Soil Survey.

Major fieldwork for this soil survey was completed in 1978-1984. Soil names anddescriptions were approved in 1986. Soil properties and interpretations were reviewedand updated in 2001. Unless otherwise indicated, statements in this publication refer toconditions in the survey area in 1986. This survey was made cooperatively by theNatural Resources Conservation Service and the Colorado Agricultural ExperimentStation and the United States Department of Interior, Bureau of Land Management. Thesurvey is part of the technical assistance furnished to the San Miguel Basin SoilConservation District. Funds for acceleration of this soil survey were provided byMontrose County, San Miguel County, San Miguel Basin Soil Conservation District, andthe Bureau of Land Management.

Soil maps in this survey may be copied without permission. Enlargement of thesemaps, however, could cause misunderstanding of the detail of mapping. If enlarged,maps do not show the small areas of contrasting soils that could have been shown at alarger scale.

The United States Department of Agriculture (USDA) prohibits discrimination in all ofits programs on the basis of race, color, national origin, gender, religion, age, disability,political beliefs, sexual orientation, and marital or family status. (Not all prohibited basesapply to all programs.) Persons with disabilities who require alternative means forcommunication of program information (Braille, large print, audiotape, etc.) shouldcontact the USDA’s TARGET Center at 202-720-2600 (voice or TDD).

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights,Room 326W, Whitten Building, 14th and Independence Avenue SW, Washington, DC20250-9410, or call 202-720-5964 (voice or TDD). USDA is an equal opportunity providerand employer.

Cover: Variations in soils and climate create a scenic mosaic of plant communities in thehigher elevations of the San Miguel Area.

http://www.usda.govhttp://www.nrcs.usda.govhttp://www.nrcs.usda.govhttp://www.ext.colostate.edu/http://www.blm.gov/nhp/index.htm

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This soil survey contains information that affects land use planning in this surveyarea. It contains predictions of soil behavior for selected land uses. The survey alsohighlights soil limitations, improvements needed to overcome the limitations, and theimpact of selected land uses on the environment.

This soil survey is designed for many different users. Farmers, ranchers, foresters,and agronomists can use it to evaluate the potential of the soil and the managementneeded for maximum food and fiber production. Planners, community officials,engineers, developers, builders, and home buyers can use the survey to plan land use,select sites for construction, and identify special practices needed to ensure properperformance. Conservationists, teachers, students, and specialists in recreation, wildlifemanagement, waste disposal, and pollution control can use the survey to help themunderstand, protect, and enhance the environment.

Various land use regulations of Federal, State, and local governments may imposespecial restrictions on land use or land treatment. The information in this report isintended to identify soil properties that are used in making various land use or landtreatment decisions. Statements made in this report are intended to help the land usersidentify and reduce the effects of soil limitations on various land uses. The landowner oruser is responsible for identifying and complying with existing laws and regulations.

Great differences in soil properties can occur within short distances. Some soils areseasonally wet or subject to flooding. Some are shallow to bedrock. Some are toounstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorlysuited to use as septic tank absorption fields. A high water table makes a soil poorlysuited to basements or underground installations.

These and many other soil properties that affect land use are described in this soilsurvey. The location of each soil is shown on the detailed soil maps. Each soil in thesurvey area is described. Information on specific uses is given for each soil. Help inusing this publication and additional information are available at the local office of theNatural Resources Conservation Service or the Cooperative Extension Service.

Allen GreenState ConservationistNatural Resources Conservation Service

Foreword

http://www.co.nrcs.usda.govhttp://www.ext.colostate.edu/

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Contents

How to Use This Soil Survey .................................. 3Foreword ................................................................. 5Soil Survey of the San Miguel Area, Colorado ... 11

General Nature of the Survey Area .................... 11History and Development ................................... 11

Water Supply ................................................. 12Agriculture ...................................................... 13Physiography, Relief, and Drainage ................ 13Natural Resources ......................................... 13Climate ........................................................... 14

How This Survey Was Made ............................... 15Detailed Soil Map Units ........................................ 17

1—Abra loam, 1 to 3 percent slopes .................. 182—Abra loam, 3 to 6 percent slopes .................. 183—Abra loam, 6 to 12 percent slopes ................ 194—Ackmen silt loam, 1 to 3 percent slopes ........ 195—Acree loam, 1 to 6 percent slopes................. 206—Acree loam, 6 to 12 percent slopes ............... 207—Acree-Zoltay-Nortez complex, 0 to 15

percent slopes ............................................. 218—Adel loam, 5 to 30 percent slopes ................. 229—Adel loam, moist, 15 to 50 percent slopes .... 2310—Aquolls, 0 to 3 percent slopes ..................... 2311—Badland ...................................................... 2412—Baird Hollow-Nordicol-Ryman complex,

5 to 40 percent slopes.................................. 2413—Barkelew-Emmons complex, 5 to 40

percent slopes ............................................. 2514—Barx fine sandy loam, 1 to 3 percent

slopes .......................................................... 2615—Barx fine sandy loam, 3 to 6 percent

slopes .......................................................... 2716—Barx fine sandy loam, 6 to 12 percent

slopes .......................................................... 2817—Barx-Progresso complex, 3 to 12 percent

slopes .......................................................... 2818—Begay fine sandy loam, 1 to 6 percent

slopes .......................................................... 2919—Beje fine sandy loam, 3 to 25 percent

slopes .......................................................... 3020—Billings silt loam, 1 to 4 percent slopes ....... 3021—Billings clay loam, moist, 1 to 4 percent

slopes .......................................................... 3122—Bodot silty clay loam, dry, 3 to 12 percent

slopes .......................................................... 31

23—Bodot, dry-Ustic Torriorthents complex, 5to 50 percent slopes .................................... 32

24—Bodot-Zyme silty clay loams, dry, 3 to 20percent slopes ............................................. 33

25—Bond-Progresso complex, 3 to 30 percentslopes .......................................................... 34

26—Borolls-Rock outcrop complex, 40 to 90percent slopes ............................................. 35

27—Burnac-Delson sandy loams, 3 to 20percent slopes ............................................. 36

28—Burnac-Delson-Falcon sandy loams, 20to 50 percent slopes .................................... 37

29—Bushvalley-Nordicol Variant complex, 2 to10 percent slopes ........................................ 38

30—Callan loam, 1 to 3 percent slopes .............. 4031—Callan loam, 3 to 6 percent slopes .............. 4032—Callan loam, 6 to 12 percent slopes ............ 4133—Callan-Gurley loams, 3 to 20 percent

slopes .......................................................... 4234—Ceek very flaggy clay loam, 10 to 40

percent slopes ............................................. 4335—Clapper loam, 1 to 8 percent slopes ........... 4336—Clapper-Ustic Torriorthents complex, 5 to

40 percent slopes ........................................ 4437—Cryaquolls, 0 to 3 percent slopes ................ 4538—Evanston fine sandy loam, 2 to 8 percent

slopes .......................................................... 4539—Falcon-Burnac-Rock outcrop complex,

3 to 20 percent slopes.................................. 4640—Farb-Rock outcrop complex, 1 to 30

percent slopes ............................................. 4741—Fivepine-Nortez-Rock outcrop complex,

12 to 30 percent slopes ................................ 4742—Fivepine-Pino loams, 0 to 15 percent

slopes .......................................................... 4943—Fluvaquents, 0 to 6 percent slopes,

frequently flooded ........................................ 5044—Fruitland loam, 1 to 8 percent slopes .......... 5045—Gladel-Bond-Rock outcrop complex, 1 to

50 percent slopes ........................................ 5146—Gladel-Bond-Rock outcrop complex, cool,

3 to 25 percent slopes.................................. 5247—Gurley loam, 1 to 8 percent slopes ............. 5348—Gurley-Skein loams, 3 to 20 percent

slopes .......................................................... 54

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49—Gypsiorthids, 3 to 25 percent slopes ........... 5550—Gypsum land .............................................. 5551—Haplaquolls, 0 to 3 percent slopes .............. 5652—Killpack-Deaver loams, 2 to 15 percent

slopes .......................................................... 5653—Leaps-Hofly loams, 5 to 40 percent

slopes .......................................................... 5754—Leaps-Tellura complex, 5 to 20 percent

slopes .......................................................... 5855—Lillylands loam, 15 to 50 percent slopes ..... 5956—Mikim loam, 1 to 6 percent slopes ............... 5957—Minchey fine sandy loam, 1 to 10 percent

slopes .......................................................... 6058—Mitch loam, 1 to 6 percent slopes ............... 6059—Mivida fine sandy loam, 5 to 15 percent

slopes .......................................................... 6160—Monogram loam, 1 to 8 percent slopes ....... 6161—Monticello-Witt loams, 1 to 3 percent

slopes .......................................................... 6362—Monticello-Witt loams, 3 to 6 percent

slopes .......................................................... 6363—Monticello-Witt loams, 6 to 12 percent

slopes .......................................................... 6464—Narraguinnep clay loam, moist, 15 to 50

percent slopes ............................................. 6565—Narraguinnep-Dapoin complex, 1 to 15

percent slopes ............................................. 6566—Nortez loam, 1 to 6 percent slopes ............. 6667—Nortez loam, 6 to 12 percent slopes ........... 6768—Nortez-Acree loams, 1 to 12 percent

slopes .......................................................... 6769—Nortez-Fivepine loams, 1 to 12 percent

slopes .......................................................... 6970—Nunemaker clay, 3 to 10 percent slopes ..... 7071—Nyswonger silty clay loam, 1 to 4 percent

slopes .......................................................... 7072—Pagoda-Coulterg-Cabba complex, 10 to

60 percent slopes ........................................ 7173—Paradox fine sandy loam, 1 to 4 percent

slopes .......................................................... 7274—Persayo-Chipeta complex, 2 to 20 percent

slopes .......................................................... 7275—Pinon-Bowdish-Progresso loams, cool,

1 to 12 percent slopes.................................. 74

76—Pinon-Bowdish-Rock outcrop complex,3 to 30 percent slopes.................................. 75

77—Pinon-Progresso loams, 3 to 12 percentslopes .......................................................... 76

78—Pinon-Ustic Torriorthents complex, 5 to30 percent slopes ........................................ 77

79—Pojoaque-Chilton complex, 5 to 30percent slopes, extremely stony ................... 78

80—Progresso loam, 1 to 3 percent slopes ........ 7981—Progresso loam, 3 to 6 percent slopes ........ 7982—Progresso loam, 6 to 12 percent slopes ...... 8083—Pulpit-Bond, cool complex, 1 to 6 percent

slopes .......................................................... 8184—Radersburg gravelly loam, 1 to 6 percent

slopes .......................................................... 8185—Radersburg gravelly loam, 6 to 30 percent

slopes .......................................................... 8286—Redlands sandy loam, 1 to 6 percent

slopes .......................................................... 8287—Rock outcrop .............................................. 8388—Rock outcrop-Orthents complex, 40 to 90

percent slopes ............................................. 8389—Ryman loam, dry, 2 to 20 percent slopes .... 8490—Ryman loam, warm, 2 to 20 percent

slopes .......................................................... 8591—Ryman-Adel, moist complex, 1 to 15

percent slopes ............................................. 8692—Sagedale clay loam, 3 to 20 percent

slopes .......................................................... 8793—Sapeha very cobbly loam, 15 to 50

percent slopes ............................................. 8794—Seitz gravelly loam, 10 to 60 percent

slopes .......................................................... 8895—Skein-Rock outcrop complex, 3 to 65

percent slopes ............................................. 8896—Skisams-Bushvalley-Cryoborolls,

moderately deep complex, 2 to 15 percentslopes .......................................................... 89

97—Skisams-Cryoborolls, moderately deepcomplex, 5 to 30 percent slopes .................. 90

98—Specie gravelly loam, 5 to 15 percentslopes .......................................................... 91

99—Specie, moist-Rock outcrop complex,15 to 60 percent slopes ................................ 91

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100—Spectacle-Kinesava loams, 5 to 30percent slopes ............................................. 92

101—Tellura-Leaps clay loams, 5 to 40percent slopes ............................................. 92

102—Typic Torriorthents, 3 to 80 percentslopes .......................................................... 93

103—Ustic Torriorthents-UstochrepticCalciorthids, 3 to 30 percent slopes ............. 94

104—Vananda silty clay, 1 to 6 percent slopes ... 94105—Winnett silty clay loam, 1 to 3 percent

slopes .......................................................... 96106—Winz-Rock outcrop complex, 20 to 90

percent slopes, very stony ........................... 96107—Witt loam, dry, 1 to 12 percent slopes ....... 97108—Wrayha stony clay loam, 3 to 40 percent

slopes .......................................................... 97109—Zoltay loam, 3 to 15 percent slopes .......... 98110—Zoltay clay loam, 1 to 3 percent slopes ..... 98111—Zyme-Bodot-Rock outcrop complex,

15 to 30 percent slopes ................................ 99112—Water ...................................................... 100

Use and Management of the Soils .................... 101Interpretive Ratings .......................................... 101

Rating Class Terms ...................................... 101Numerical Ratings ........................................ 101

Crops and Pasture ........................................... 101Yields per Acre ............................................. 103Land Capability Classification ...................... 103Prime Farmland ........................................... 104

Ecological Sites and Characteristic NativeVegetation .................................................. 105

Rangeland ........................................................ 105Forest Productivity and Management ............... 107

Forest Productivity ....................................... 107Forest Management ..................................... 108

Recreation ........................................................ 109Wildlife Habitat ................................................. 111Engineering ...................................................... 112

Building Site Development ........................... 113Sanitary Facilities ......................................... 114Construction Materials ................................. 116Water Management ...................................... 117

Soil Properties .................................................... 119Engineering Index Properties ........................... 119Physical Properties .......................................... 120

Chemical Properties ......................................... 121Water Features ................................................. 122Soil Features .................................................... 123

Classification of the Soils .................................. 125Soil Series and Their Morphology ..................... 125

Abra Series .................................................. 125Ackmen Series ............................................. 126Acree Series ................................................ 127Adel Series .................................................. 127Aquolls ......................................................... 128Baird Hollow Series ...................................... 129Barkelew Series ........................................... 129Barx Series .................................................. 130Begay Series................................................ 131Beje Series .................................................. 131Billings Series .............................................. 132Bodot Series ................................................ 132Bond Series ................................................. 133Borolls .......................................................... 133Bowdish Series ............................................ 134Burnac Series .............................................. 135Bushvalley Series ........................................ 135Cabba Series ............................................... 136Callan Series ............................................... 136Ceek Series ................................................. 137Chilton Series .............................................. 137Chipeta Series ............................................. 138Clapper Series ............................................. 138Coulterg Series ............................................ 139Cryaquolls .................................................... 140Cryoborolls ................................................... 140Dapoin Series .............................................. 141Deaver Series .............................................. 141Delson Series .............................................. 142Emmons Series ........................................... 142Evanston Series ........................................... 143Falcon Series ............................................... 144Farb Series .................................................. 144Fivepine Series ............................................ 145Fluvaquents ................................................. 145Fruitland Series ............................................ 145Gladel Series ............................................... 146Gurley Series ............................................... 146Gypsiorthids ................................................. 147Haplaquolls .................................................. 148

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Issued 2003

Hofly Series ................................................. 148Killpack Series ............................................. 149Kinesava Series ........................................... 149Leaps Series ................................................ 150Lillylands Series ........................................... 150Mikim Series ................................................ 151Minchey Series ............................................ 151Mitch Series ................................................. 152Mivida Series ............................................... 152Monogram Series ......................................... 153Monticello Series .......................................... 154Narraguinnep Series .................................... 155Nordicol Series ............................................ 155Nordicol Variant ............................................ 156Nortez Series ............................................... 156Nunemaker Series ....................................... 157Nyswonger Series ........................................ 158Orthents ....................................................... 158Pagoda Series ............................................. 159Paradox Series ............................................. 160Persayo Series ............................................. 160Pino Series .................................................. 161Pinon Series ................................................ 161Pojoaque Series ........................................... 162Progresso Series ......................................... 162Pulpit Series ................................................. 163Radersburg Series ....................................... 163Redlands Series........................................... 164Ryman Series .............................................. 164Sagedale Series ........................................... 165Sapeha Series ............................................. 166Seitz Series .................................................. 166Skein Series ................................................. 167Skisams Series ............................................ 167Specie Series ............................................... 168Spectacle Series .......................................... 168Tellura Series ............................................... 169Typic Torriorthents ........................................ 170Ustic Torriorthents ........................................ 170Ustochreptic Calciorthids ............................. 170Vananda Series ............................................ 171Winnett Series.............................................. 171Winz Series .................................................. 172

Witt Series ................................................... 173Wrayha Series ............................................. 173Zoltay Series ................................................ 174Zyme Series ................................................. 175

Formation of the Soils ........................................ 177References .......................................................... 179Glossary .............................................................. 181Tables .................................................................. 193

Table 1.--Temperature and precipitation ........... 195Table 2.--Freeze dates in spring and fall ........... 198Table 3.--Growing season................................. 201Table 4.--Acreage and proportionate extent

of the soils ................................................. 203Table 5A.--Land capability and yields per

acre of crops and pasture .......................... 206Table 5B.--Land capability and yields per

acre of crops and pasture .......................... 213Table 6.--Prime farmland .................................. 214Table 7.--Ecological sites and characteristic

native vegetation ........................................ 215Table 8.--Forest productivity ............................. 250Table 9A.--Forestland management .................. 254Table 9B.--Forestland management .................. 260Table 9C.--Forestland management ................. 265Table 9D.--Forestland management .................. 270Table 9E.--Forestland management .................. 275Table 10A.--Recreation ..................................... 279Table 10B.--Recreation ..................................... 298Table 11.--Wildlife habitat ................................. 312Table 12A.--Building site development .............. 321Table 12B.--Building site development .............. 336Table 13A.--Sanitary facilities ........................... 353Table 13B.--Sanitary facilities ........................... 370Table 14A.--Construction materials .................. 384Table 14B.--Construction materials ................... 397Table 15.--Water management ......................... 417Table 16.--Engineering index properties ........... 429Table 17.--Physical properties of the soils ........ 453Table 18--Chemical properties of the soils ........ 467Table 19.--Water features ................................. 481Table 20.--Soil features ..................................... 489Table 21.--Classification of the soils ................. 497

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General Nature of the Survey AreaThe San Miguel Area is in the southwestern corner

of Colorado. It has a total area of 1,247,542 acres, orabout 1,949 square miles (fig. 1). The area encompassesparts of Dolores, Montrose, and San Miguel Counties.Dove Creek is the county seat of Dolores County,Montrose the county seat of Montrose County, andTelluride the county seat of San Miguel County. Othercommunities in the area are Egnar, Nucla, Naturita,Redvale, Norwood, Uravan, Placerville, Sawpit,Bedrock, Paradox, and Slickrock. Dove Creek,Montrose, and Telluride are located outside the surveyarea. The population of the area is about 3,150.

The area is predominantly Federally-administered

land. About 70 percent is administered by the UnitedStates Department of the Interior, Bureau of LandManagement, and the United States Department ofAgriculture, Forest Service. The State of Coloradoadministers 1.5 percent of the area. The Dolores Riverflows through the area from south to north; its majortributaries are the San Miguel River and the Leopard,Saltado, Specie, Fall, Bear, Disappointment, Dry, andNaturita Creeks, and the Maverick Draw.

Elevation ranges from about 4,900 feet in theParadox Valley to about 10,000 feet north of LastDollar Mountain, on the National Forest boundary.

The climate of the survey area ranges from that ofa warm desert in Disappointment Valley to that of cool,subhumid areas on the mesas and mountains belowthe Uncompahgre National Forest.

The area mainly is used as rangeland. Raisingcattle, sheep, and horses is important to the economy.The area also is used as irrigated and nonirrigatedcropland.

Uranium mining is active in the western part of thearea when the price for uranium is favorable. Open pitcoal mining is active in the Nucla area when coalprices are favorable. There is some natural gasdevelopment in the Dry Creek Basin.

History and Development

The Ute Indians occupied the survey area whenFranciscan friars Dominguez and Escalante passedthrough it in 1776. The friars were seeking a land routeto Spanish missions in California. The friars camped at

Soil Survey of

San Miguel Area, ColoradoParts of Dolores, Montrose, and San MiguelCounties

By William S. Hawn, Natural Resources Conservation ServiceQuality Assurance by Thomas Hahn, Natural Resources Conservation Service

Fieldwork by William S. Hawn, Joseph A. Pepi, Mary C. Currie, Richard B. Trenholme,James, L. Fuchs, Glenn R. Dunavan, William R. Hunter, and Wayne L. Johannson.

United States Department of Agriculture, Natural Resources Conservation Service,in cooperation withthe Colorado Agricultural Experiment Station; United States Department of the Interior,Bureau of Land Management; San Miguel County; and San Miguel Basin SoilConservation District.

Figure 1.—Location of the San Miguel Area in Colorado.

12 Soil Survey

the confluence of Dry Creek and the San Miguel Riveron August 21, 1776.

The first permanent settlement in the Norwood areawas in about 1881. In 1887, other settlers begancoming in and filing on land. Norwood had a populationof 50 in 1881 and was incorporated in 1905. Raisinglivestock and farming were important to the area in theearly days, and continue to be important today.

Grass hay, alfalfa, and small grains are grown forlivestock feed. Large acreages of land administered bythe Bureau of Land Management and Forest Serviceare used for livestock grazing in spring, summer, andfall.

Logging has been fairly active at times in the surveyarea.

A long history of uranium mining that dates back tothe 1880’s has shaped the current socioeconomicfactor in the survey area since the late 1940s,especially when the price for uranium is favorable.Since World War II, the establishment of the AtomicEnergy Commission and the creation of a peacetimenuclear power industry have increased the demand foruranium. Mining uranium and processing ore havebeen important industries in the area.

There are some small coal mines in the surveyarea and also a few oil and gas wells.

Some small parts of the survey area are irrigated.These include West Paradox Valley, the Nucla area,Wrights Mesa, and other very small isolated areas.The main limitation to irrigation is the lack of sufficientirrigation water.

Extensive dryland farming acreage is in the Egnararea. Pinto beans and winter wheat are grown in thisarea. The acreage is in an extensive tableland areathat is characterized by eolian deposits.

The San Miguel Area is a plateau countrycharacterized by many mesas that are dissected bysteep canyons (fig. 2). It supports large acreages oftwoneedle pinyon and Utah juniper stands.

Water Supply

The San Miguel River is the principal source ofsurface water in the survey area. Other streams arethe Dolores River; Naturita, Disappointment,Tabeguache, Dry, Leopard, Specie, Fall, West Paradox,and Beaver Creeks; and the Maverick Draw.

Snowmelt from the San Juan Mountains and theUncompahgre Plateau yields the major flow for therivers and creeks in the survey area.

The main reservoirs in the survey area, whichprovide water for irrigation, domestic use, andhydroelectric production, are the Gurley, Lone Cone,Miramonte, Buckeye, and Groundhog Reservoirs.

Diversion ditches from streams coming off of theLone Cone Mountain are used to fill the Gurley andLone Cone Reservoirs. The Miramonte Reservoir wascreated by the damming of West Naturita Creek. Damsconstructed on West Paradox and Groundhog Creeks,respectively, created the Buckeye and GroundhogReservoirs.

The distribution of the irrigation water stored inthese reservoirs is done by several main transmissionditches. These ditches are the Gurley, ColoradoCooperative, Lone Cone, and Wray ditches. The Gurleyand Lone Cone ditches provide the water that is usedto irrigate about 12,000 acres on Wrights Mesa, nearthe towns of Norwood and Redvale. The ColoradoCooperative ditch diverts water from the San MiguelRiver at Pinyon and transports it to the Nucla area,where approximately 11,000 acres of land is irrigated.There are approximately 4,500 acres of irrigated landin the Paradox Valley, which receives water from theBuckeye Reservoir via the Wray ditch. There also aresome other minor ditches that divert from smallstreams for irrigation of scattered areas of farmland.This land is mainly in alluvial areas adjacent to thestreams from which the water is diverted.

The main method of irrigation is flooding fromcontour ditches and pumped and gravity-pressuredsprinkler irrigation systems. For the most part, thesesprinkler systems are the side-roll type, although thereare several center-pivot systems. Gated-pipe irrigationsystems are also used on irrigated land where suitable.These new irrigation systems have increased water

Figure 2.—Shown is a typical landscape of mesas, structuralbenches, and valley floors.

San Miguel Area, Colorado 13

use efficiency by reducing water use while maintainingor improving crop yields.

Agriculture

by Jack Warren, District Conservationist, Natural ResourcesConservation Service

Many thousands of head of both cattle and sheepwere raised in the early 1900s. Hay and pasture,irrigated by diverted surface waters, supplemented thehigh country summer grazing. Norwood was a hub forthis livestock enterprise which later spread towardsthe west.

To the south, east, and north from Norwood is therough and high terrain so well suited for grazing andtimber production. To the west, the growing seasonlengthens and the agriculture picture is broader. FromCoventry Hill towards Redvale, then on into Nucla,small apple orchards were established. Grainproduction, corn, and other vegetables became moreapparent. In the west end of Montrose County, theclimate is excellent for production when irrigation isadequately provided. The dryland farming areasurrounding Egnar has been used for wheat and pintobean production for over 50 years.

Today, livestock numbers have greatly declined.Most crops are produced for local use, the exceptionsbeing wheat and beans from the Egnar area.

Recreation has stepped strongly ahead, greatlyimpacting this survey area. Telluride Ski Area (adjacentto this area), and related winter sport activities, year-round fishing, and fee hunting lead in monetaryinfluence. Land lease and sales for recreational usehas increased, most dramatically from Telluride(outside this area), and extending into the area aroundNorwood.

The San Miguel Basin Soil Conservation Districtwas formed in 1957. This was allowed by theconsolidation of three districts: the Tabeguache,Norwood, and Paradox, all of which were organized in1937. Additional land was added to the District by anelection in 1958 and by a transfer from the Dove CreekDistrict in 1978. This combined District remains theleader for all conservation activities in the San MiguelBasin Survey Area.

Physiography, Relief, and Drainage

The survey area is in the plateau country ofsouthwestern Colorado. The major physiographicfeatures in the area are the Sinbad Valley, Big andLittle Gypsum Valleys, and Paradox Valley, all of whichwere formed by the collapse of anticlines. The DryCreek Basin and Disappointment Valley also are major

physiographic features. The entire survey area consistsof valleys and basins separated by mesas. Some ofthese mesas lie 1,000 to 2,000 feet above the valleys.

Total relief within the area is about 5,100 feet.Elevation ranges from about 4,900 feet in the ParadoxValley to about 10,000 feet north of Last DollarMountain on the National Forest boundary.

The survey area is drained by the San Miguel andDolores Rivers and their tributaries (fig. 3). The San Miguel River drains the San Juan Mountains and runsnorthwest through the survey area. The Dolores Riveralso drains the San Juan Mountains and runs fromsouth to north through the western part of the surveyarea, and joins the San Miguel River north of Uravan.

Natural Resources

Soil, surface water, oil, natural gas, uranium, sand,gravel, coal, and native vegetation are the majornatural resources of the survey area. Soil, the mostwidely used of the survey area’s resources, can beexpected to yield benefits without depletion if managedand used properly. The purpose of this survey is to aidin maintaining and improving the value of the soilresource.

The San Miguel and Dolores Rivers andDisappointment Creek are the principal sources ofsurface water.

Figure 3.—The floodplain and terraces of the Dolores Riverare bounded by steep canyons in the western part ofthe area.

14 Soil Survey

The Dry Creek Basin has a few gas wells as doesthe Horse Range Mesa. The number of oil wells in thesurvey area is minimal. There are a few small coalmine operations, mostly in the Nucla area.

Sand and gravel sources for building roads andother structures are present along the San Miguel andDolores Rivers, and also on terraces on Wright’s Mesaand south of it.

Uranium ore is mined from the Saltwash Member ofthe Morrison Formation. There has been a cyclicalboom and bust in the uranium industry from the late1940’s until the present time.

Rangeland is the most important agriculturalresource in this survey area. There is some timberproduction around Norwood.

Principal game animals are elk, mule deer, coyote,mountain lion, black bear, and cottontail.

Climate

Prepared by the Natural Resources Conservation ServiceNational Water and Climate Center, Portland, Oregon.

The climate tables are created from climate stationsat Norwood, Telluride and Uravan, Colorado. Additionalprecipitation and temperature information for thissurvey was obtained from new high resolution climatemaps, derived using the PRISM modeling system atOregon State University. Thunderstorm days, relativehumidity, percent sunshine, and wind information areestimated from First Order station at Grand Junction,Colorado.

Table 1 gives data on temperature and precipitationfor the survey area as recorded at Norwood, Telluride,and Uravan, Colorado in the period 1961 to 1990. Table2 shows probable dates of the first freeze in fall andthe last freeze in spring. Table 3 provides data on thelength of the growing season.

In winter, the average temperatures are 25.0, 23.3,and 31.2 degrees F, respectively, at Norwood, Telluride,and Uravan; the respective average daily minimumtemperatures in winter are 11.2, 7.9, and 18.0 degreesF. The lowest temperatures on record were -31o F atNorwood on January 12, 1963; -36o F at Telluride onFebruary 8, 1933; and -23o F at Uravan on January 13,1963.

In summer, the average temperatures are 63.7o F,57.8o F, and 74.1o F, respectively, at Norwood, Telluride,and Uravan. The respective average daily maximumtemperatures are 80.8o F, 75.5o F, and 92.0o F. Thehighest temperatures in the respective periods ofrecord were 97o F at Norwood on June 25, 1981; 96o Fat Telluride on July 15, 1922; and 110o F at Uravan onJuly 7, 1989.

Growing degree days are shown in Table 1. They areequivalent to “heat units.” During the month, growingdegree days accumulate by the amount that theaverage temperature each day exceeds a basetemperature (40 degrees F). The normal monthlyaccumulation is used to schedule single or successiveplantings of a crop between the last freeze in springand the first freeze in fall.

Average annual precipitation over this survey areais quite variable and mainly is dependent uponelevation. In general, the western plateau and valleyareas receive between 10 and 15 inches ofprecipitation per year. In the higher mountains above9,000 feet, average annual precipitation is as much as40 inches on the border between Dolores and SanMiguel counties. The average annual total precipitationat the three climate stations is about 15.4 inches atNorwood, 23.6 inches at Telluride, and 12.6 inches atUravan. The growing season is only 50 to 80 days longin the higher mountains, but is over 160 days long, onaverage, at Uravan. At Uravan, about 7 inches ofprecipitation normally falls between May and October,which is the normal growing season. This 7 inchesrepresents about 56 percent of the average annualtotal. The heaviest 1-day precipitation amounts duringthe periods of record (going back to 1948 at Norwood,1901 at Telluride, and 1961 at Uravan) were 2.90inches at Norwood on October 3, 1996; 3.50 inches atTelluride on August 26, 1914; and 1.90 inches atUravan on August 21, 1971. Thunderstorms occur onabout 35 days each year at lower elevations, but aresomewhat more frequent at higher elevations. Mostthunderstorms occur in the San Miguel Area in Julyand August.

The average seasonal snowfall is also verydependent on elevation. Only 10 inches of snowtypically falls during a given year at Uravan and otherlower-elevation valley locations in the western part ofthe survey area; however, snowfall dramaticallyincreases to the east with elevation. At Norwood,average annual snowfall is 63 inches, and it is 194inches at Telluride. Average number of days with atleast one inch of snow on the ground ranges from just5 at Uravan, to 20 to 30 at Norwood, and more than105 at Telluride. The greatest snow depths at any onetime during the periods of record were 28 inches atNorwood, recorded on March 2, 1960; 64 inches atTelluride, recorded on February 8, 1949; and just 10inches at Uravan, recorded on December 15, 1967.The heaviest 1-day snowfalls on record were 12.0inches at Norwood, recorded on February 18, 1955;28.5 inches at Telluride, recorded on April 2, 1903; and9.0 inches at Uravan, recorded on January 25, 1967.


The average relative humidity in mid-afternoon isabout 35 percent at lower elevations. Humidity ishigher at night, and the average at dawn is about 60percent at lower elevations. The sun shines 78 percentof the time in summer and 60 percent in winter. Theprevailing wind is from the southwest. Average windspeed is highest, around 10 miles per hour, from Aprilto July, but is highly affected by exposure andelevation.

How This Survey Was MadeThis survey was made to provide information about

the soils and miscellaneous areas in the survey area.The information includes a description of the soils andmiscellaneous areas and their location and adiscussion of their suitability, limitations, andmanagement for specified uses. Soil scientistsobserved the steepness, length, and shape of theslopes; the general pattern of drainage; the kinds ofcrops and native plants; and the kinds of bedrock.They dug many holes to study the soil profile, whichis the sequence of natural layers, or horizons, in a soil.The profile extends from the surface down into theunconsolidated material in which the soil formed. Theunconsolidated material is devoid of roots and otherliving organisms and has not been changed by otherbiological activity.

The soils and miscellaneous areas in the surveyarea are in an orderly pattern that is related to thegeology, landforms, relief, climate, and naturalvegetation of the area. Each kind of soil andmiscellaneous area is associated with a particular kindof landform or with a segment of the landform. Byobserving the soils and miscellaneous areas in thesurvey area and relating their position to specificsegments of the landform, a soil scientist develops aconcept or model of how they were formed. Thus,during mapping, this model enables the soil scientistto predict with a considerable degree of accuracy thekind of soil or miscellaneous area at a specific locationon the landscape.

Commonly, individual soils on the landscape mergeinto one another as their characteristics graduallychange. To construct an accurate soil map, however,soil scientists must determine the boundaries betweenthe soils. They can observe only a limited number ofsoil profiles. Nevertheless, these observations,supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient toverify predictions of the kinds of soil in an area andto determine the boundaries.

Soil scientists recorded the characteristics of thesoil profiles that they studied. They noted soil color,

texture, size and shape of soil aggregates, kind andamount of rock fragments, distribution of plant roots,reaction, and other features that enable them toidentify soils. After describing the soils in the surveyarea and determining their properties, the soilscientists assigned the soils to taxonomic classes(units). Taxonomic classes are concepts. Eachtaxonomic class has a set of soil characteristics withprecisely defined limits. The classes are used as abasis for comparison to classify soils systematically.Soil taxonomy, the system of taxonomic classificationused in the United States, is based mainly on the kindand character of soil properties and the arrangementof horizons within the profile. After the soil scientistsclassified and named the soils in the survey area, theycompared the individual soils with similar soils in thesame taxonomic class in other areas so that theycould confirm data and assemble additional databased on experience and research.

While a soil survey is in progress, samples of someof the soils in the area generally are collected forlaboratory analyses and for engineering tests. Soilscientists interpret the data from these analyses andtests as well as the field-observed characteristics andthe soil properties to determine the expected behaviorof the soils under different uses. Interpretations for allof the soils are field tested through observation of thesoils in different uses and under different levels ofmanagement. Some interpretations are modified to fitlocal conditions, and some new interpretations aredeveloped to meet local needs. Data are assembledfrom other sources, such as research information,production records, and field experience of specialists.For example, data on crop yields under defined levelsof management are assembled from farm records andfrom field or plot experiments on the same kinds ofsoil.

Predictions about soil behavior are based not onlyon soil properties but also on such variables asclimate and biological activity. Soil conditions arepredictable over long periods of time, but they are notpredictable from year to year. For example, soilscientists can predict with a fairly high degree ofaccuracy that a given soil will have a high water tablewithin certain depths in most years, but they cannotpredict that a high water table will always be at aspecific level in the soil on a specific date.

After soil scientists located and identified thesignificant natural bodies of soil in the survey area,they drew the boundaries of these bodies on aerialphotographs and identified each as a specific mapunit. Aerial photographs show trees, buildings, fields,roads, and rivers, all of which help in locatingboundaries accurately.

16

The descriptions, names, and delineations of thesoils in this survey area do not fully agree with thoseof the soils in adjacent survey areas. Differences arethe result of a better knowledge of soils,

modifications in series concepts, or variations in theintensity of mapping or in the extent of the soils in thesurvey areas.

17

The map units delineated on the detailed soilmaps in this survey represent the soils ormiscellaneous areas in the survey area. The map unitdescriptions in this section, along with the maps, canbe used to determine the suitability and potential of aunit for specific uses. They also can be used to planthe management needed for those uses.

A map unit delineation on a soil map represents anarea dominated by one or more major kinds of soil ormiscellaneous areas. A map unit is identified andnamed according to the taxonomic classification ofthe dominant soils. Within a taxonomic class thereare precisely defined limits for the properties of thesoils. On the landscape, however, the soils arenatural phenomena, and they have the characteristicvariability of all natural phenomena. Thus, the rangeof some observed properties may extend beyond thelimits defined for a taxonomic class. Areas of soilsof a single taxonomic class rarely, if ever, can bemapped without including areas of other taxonomicclasses. Consequently, every map unit is made up ofthe soils or miscellaneous areas for which it is namedand some minor components that belong totaxonomic classes other than those of the majorsoils.

Most minor soils have properties similar to thoseof the dominant soil or soils in the map unit, and thusthey do not affect use and management. These arecalled noncontrasting, or similar, components. Theymay or may not be mentioned in a particular map unitdescription. Other minor components, however, haveproperties and behavioral characteristics divergentenough to affect use or to require differentmanagement. These are called contrasting, ordissimilar, components. They generally are in smallareas and could not be mapped separately becauseof the scale used. Some small areas of stronglycontrasting soils or miscellaneous areas areidentified by a special symbol on the maps. Thecontrasting components are mentioned in the mapunit descriptions. A few areas of minor componentsmay not have been observed, and consequently theyare not mentioned in the descriptions, especially

where the pattern was so complex that it wasimpractical to make enough observations to identifyall the soils and miscellaneous areas on thelandscape.

The presence of minor components in a map unitin no way diminishes the usefulness or accuracy ofthe data. The objective of mapping is not to delineatepure taxonomic classes but rather to separate thelandscape into landforms or landform segments thathave similar use and management requirements. Thedelineation of such segments on the map providessufficient information for the development of resourceplans. If intensive use of small areas is planned,however, onsite investigation is needed to define andlocate the soils and miscellaneous areas.

An identifying symbol precedes the map unit namein the map unit descriptions. Each descriptionincludes general facts about the unit and gives theprincipal hazards and limitations to be considered inplanning for specific uses of the map unit.

In the descriptions that follow, values are given forselected soil chemical and physical properties. Formany properties, representative values and ratingsfor the whole soil are given. For some chemicalproperties maximum values are given. These refer tothe highest value for the given property that cantypically be expected in one or more layers within thesoil profile. Values this high may not berepresentative. For more detailed information on soilchemical and physical properties, including the fullranges of values for each horizon, see the tablesdescribed in the "Soil Properties" section.

Soils that have profiles that are almost alike makeup a soil series. Except for differences in texture ofthe surface layer, all the soils of a series have majorhorizons that are similar in composition, thickness,and arrangement.

Soils of one series can differ in texture of thesurface layer, slope, stoniness, salinity, degree oferosion, and other characteristics that affect their use.On the basis of such differences, a soil series isdivided into soil phases. Most of the areas shown onthe detailed soil maps are phases of soil series. The

Detailed Soil Map Units

18 Soil Survey

name of a soil phase commonly indicates a featurethat affects use or management. For example, Zoltayclay loam, 1 to 3 percent slopes is a phase of theZoltay series.

Some map units are made up of two or moremajor soils or miscellaneous areas. These map unitsare complexes, associations, or undifferentiatedgroups.

A complex consists of two or more soils ormiscellaneous areas in such an intricate pattern orin such small areas that they cannot be shownseparately on the maps. The pattern and proportionof the soils or miscellaneous areas are somewhatsimilar in all areas. Pagoda-Coulterg-Cabba complex,10 to 60 percent slopes is an example.

This survey includes miscellaneous areas. Suchareas have little or no soil material and support littleor no vegetation. Badland is an example.

Table 4 gives the acreage and proportionate extentof each map unit. Other tables give properties of thesoils and the limitations, capabilities, and potentialsfor many uses. The Glossary defines many of theterms used in describing the soils or miscellaneousareas.

1—Abra loam, 1 to 3 percent slopes

Map Unit Setting

Major Land Resource Area: 35Elevation: 5,500 to 6,800 feet (1,676 to 2,073 meters)Mean annual precipitation: 10 to 14 inches (254 to

356 millimeters)Average annual air temperature: 47 to 49 degrees F

(8 to 10 degrees C)Frost-free period: 110 to 130 days

Map Unit Composition

Abra and similar soils: 85 percentMinor components: 15 percent

Component Descriptions

Abra soils

Landform: Terrace, alluvial fan, valley floorParent material: Alluvium derived from sandstoneSlope: 1 to 3 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 7.5 inches (moderate)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than

72 inchesRunoff class: Low

Calcium carbonate maximum: About 40 percentGypsum maximum: About 5 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Ecological site: Semidesert LoamPotential native vegetation: Wyoming big sagebrush,

needleandthread, blue grama, bottlebrushsquirreltail, galleta

Land capability subclass (irrigated): 2eLand capability subclass (nonirrigated): 4c

Typical profile:0 to 3 inches—loam3 to 13 inches—loam13 to 32 inches—loam32 to 60 inches—gravelly sandy loam

Minor Components

Barx and similar soilsComposition: About 5 percent

Clapper and similar soilsComposition: About 5 percent

Progresso and similar soilsComposition: About 5 percent

Major Uses

Livestock grazing in spring and fall, wildlife habitat,cropland


Map Unit Setting







Abra soils

Landform: Alluvial fan, valley floor, terraceParent material: Alluvium derived from sandstoneSlope: 3 to 6 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 7.5 inches (moderate)Shrink-swell potential: About 1.5 percent (low)


Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: MediumCalcium carbonate maximum: About 40 percentGypsum maximum: About 5 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Ecological site: Semidesert LoamPotential native vegetation: Wyoming big sagebrush,




Minor Components




Major Uses



Map Unit Setting







Abra soils

Landform: Alluvial fan, valley floor, terraceParent material: Alluvium derived from sandstone

Slope: 6 to 12 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 7.5 inches (moderate)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: MediumCalcium carbonate maximum: About 40 percentGypsum maximum: About 5 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Ecological site: Semidesert LoamPotential native vegetation: Wyoming big sagebrush,


Land capability subclass (irrigated): 4eLand capability subclass (nonirrigated): 6e


Minor Components




Major Uses


4—Ackmen silt loam, 1 to 3 percentslopes

Map Unit Setting





Ackmen and similar soils: 90 percentMinor components: 10 percent

20 Soil Survey


Ackmen soils

Landform: Flood plainParent material: Alluvium derived from eolian materialSlope: 1 to 3 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 9.5 inches (high)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: RareDepth to seasonal high water table: Greater than 72

inchesRunoff class: LowCalcium carbonate maximum: About 10 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Sodicity maximum: Sodium adsorption ratio about 5

(slightly sodic)Ecological site: Loamy FoothillsPotential native vegetation: muttongrass, western

wheatgrass, Wyoming big sagebrush, Indianricegrass, Utah serviceberry, black sagebrush,bottlebrush squirreltail, yellow rabbitbrush

Land capability subclass (nonirrigated): 3c

Typical profile:0 to 5 inches—silt loam5 to 41 inches—silt loam, loam41 to 60 inches—loam

Minor Components

Monticello and similar soilsComposition: About 5 percent

Pulpit and similar soilsComposition: About 5 percent

Major Uses

Cropland, livestock grazing, wildlife habitat

5—Acree loam, 1 to 6 percent slopes

Map Unit Setting

Major Land Resource Area: 48AElevation: 7,400 to 8,500 feet (2,256 to 2,591 meters)Mean annual precipitation: 17 to 19 inches (432 to




Acree and similar soils: 85 percentMinor components: 15 percent


Acree soils

Landform: Structural bench, mesaParent material: Alluvium derived from sandstone

and shaleSlope: 1 to 6 percentDrainage class: Well drainedSlowest permeability: SlowAvailable water capacity: About 9.2 inches (high)Shrink-swell potential: About 7.5 percent (high)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: HighCalcium carbonate maximum: About 15 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Ecological site: Mountain LoamPotential native vegetation: Arizona fescue, Parry’s

danthonia, mountain muhly, western wheatgrass,mountain big sagebrush, nodding brome, slenderwheatgrass

Land capability subclass (irrigated): 4cLand capability subclass (nonirrigated): 4c

Typical profile:0 to 8 inches—loam8 to 30 inches—clay, clay loam30 to 60 inches—clay loam

Minor ComponentsNortez and similar soils

Composition: About 5 percentZoltay and similar soils

Composition: About 5 percentRock outcrop

Composition: About 5 percent

Major Uses

Livestock grazing in summer and fall, wildlifehabitat, cropland

6—Acree loam, 6 to 12 percent slopes

Map Unit Setting

Major Land Resource Area: 48AElevation: 7,400 to 8,500 feet (2,256 to 2,591 meters)Mean annual precipitation: 17 to 19 inches (432 to





Acree and similar soils: 85 percentMinor components: 15 percent


Acree soils

Landform: Mesa, structural benchParent material: Alluvium derived from sandstone


inchesRunoff class: Very highCalcium carbonate maximum: About 15 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Ecological site: Mountain LoamPotential native vegetation: Arizona fescue, Parry’s




Minor Components

Nortez and similar soilsComposition: About 5 percent

Zoltay and similar soilsComposition: About 5 percent

Rock outcropComposition: About 5 percent

Major Uses

Livestock grazing in summer and fall, wildlifehabitat, pasture, cropland

7—Acree-Zoltay-Nortez complex, 0 to 15percent slopes

Map Unit Setting

Major Land Resource Area: 48AElevation: 7,600 to 8,500 feet (2,316 to 2,591 meters)

Mean annual precipitation: 17 to 19 inches (432 to483 millimeters)

Average annual air temperature: 43 to 45 degrees F(6 to 7 degrees C)

Frost-free period: 70 to 90 days


Acree and similar soils: 45 percentZoltay and similar soils: 25 percentNortez and similar soils: 20 percentMinor components: 10 percent


Acree soils

Landform: MesaParent material: Alluvium derived from sandstone


inchesRunoff class: Very highCalcium carbonate maximum: About 15 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Ecological site: Mountain LoamPotential native vegetation: Arizona fescue, Parry’s


Land capability subclass (nonirrigated): 4e


Zoltay soils


and shaleSlope: 0 to 15 percentDrainage class: Well drainedSlowest permeability: SlowAvailable water capacity: About 7.9 inches (moderate)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than

72 inches

22 Soil Survey

Runoff class: Very highCalcium carbonate maximum: About 15 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Ecological site: Mountain Clay LoamPotential native vegetation: Arizona fescue, Gambel’s

oak, mountain muhly, western wheatgrass,Letterman’s needlegrass, muttongrass


Typical profile:0 to 6 inches—loam6 to 14 inches—clay loam14 to 29 inches—cobbly clay29 to 46 inches—very cobbly clay loam46 to 60 inches—cobbly clay loam

Nortez soils


and shaleSlope: 0 to 15 percentDepth to restrictive feature: 20 to 40 inches to

bedrock (lithic)Drainage class: Well drainedSlowest permeability: SlowAvailable water capacity: About 5.4 inches (low)Shrink-swell potential: About 7.5 percent (high)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: HighCalcium carbonate maximum: About 10 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Ecological site: Pine GrasslandsPotential native vegetation: ponderosa pine, Arizona

fescue, needleandthread, Parry’s danthonia,mountain muhly, western wheatgrass, Gambel’soak, antelope bitterbrush, mountain bigsagebrush, mountain brome, prairie Junegrass


Typical profile:0 to 8 inches—loam8 to 24 inches—clay loam, cobbly clay loam24 to 32 inches—loam32 to 36 inches—unweathered bedrock

Minor Components

Sagedale and similar soilsComposition: About 5 percentLandform: Drainageway

Nunemaker and similar soilsComposition: About 5 percentLandform: Drainageway

Major Uses

Livestock grazing in summer, wildlife habitat

8—Adel loam, 5 to 30 percent slopes

Map Unit Setting

Major Land Resource Area: 48AElevation: 9,000 to 10,000 feet (2,743 to 3,048

meters)Mean annual precipitation: 22 to 24 inches (559 to




Adel and similar soils: 80 percentMinor components: 20 percent


Adel soils

Landform: Mountain slope, mesa, hillParent material: Till and residuum derived from shale

and sandstoneSlope: 5 to 30 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 8.5 inches (moderate)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: MediumCalcium carbonate maximum: NoneEcological site: Subalpine LoamPotential native vegetation: Thurber’s fescue, Parry’s

danthonia, Arizona fescue, nodding brome, silversagebrush


Typical profile:0 to 50 inches—loam50 to 60 inches—clay loam

Minor Components

Ryman and similar soilsComposition: About 10 percentSlope: 0 to 5 percent

Cryoborolls, bouldery surface and similar soilsComposition: About 10 percentSlope: 5 to 30 percent


Major Uses


9—Adel loam, moist, 15 to 50 percentslopes

Map Unit Setting

Major Land Resource Area: 48AElevation: 8,500 to 10,000 feet (2,591 to 3,048

meters)Mean annual precipitation: 26 to 30 inches (660 to




Adel and similar soils: 90 percentMinor components: 10 percent


Adel soils

Landform: Mountain slopeParent material: Residuum weathered from

interbedded sandstone and shaleSlope: 15 to 50 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 8.5 inches (moderate)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: HighCalcium carbonate maximum: NoneEcological site: Quaking AspenPotential native vegetation: quaking aspen, slender

wheatgrass, elk sedge, Arizona fescue, Thurber’sfescue, blue wildrye, mountain brome, mountainsnowberry, nodding brome


Typical profile:0 to 50 inches—loam50 to 60 inches—clay loam

Minor Components

Cryoborolls and similar soilsComposition: About 10 percent

Major Uses


10—Aquolls, 0 to 3 percent slopes

Map Unit Setting





Aquolls and similar soils: 95 percentMinor components: 5 percent


Aquolls soils

Landform: Slough, flood plainParent material: Alluvium from mixed sourcesSlope: 0 to 3 percentDrainage class: Very poorly drainedSlowest permeability: Moderately slowAvailable water capacity: About 9.8 inches (high)Shrink-swell potential: About 4.5 percent (moderate)Hazard of flooding: FrequentDepth to seasonal high water table: 12 to 36 inchesRunoff class: MediumCalcium carbonate maximum: About 10 percentSalinity maximum: About 4 mmhos/cm (very slightly

saline)Ecological site: Salt MeadowPotential native vegetation: alkali sacaton, inland

saltgrass, sedge, western wheatgrass, fourwingsaltbush, greasewood, tall rabbitbrush

Land capability subclass (irrigated): 5wLand capability subclass (nonirrigated): 5w

Typical profile:0 to 3 inches—clay loam3 to 21 inches—clay loam21 to 38 inches—clay loam38 to 60 inches—sandy clay loam

Minor Components

Nyswonger and similar soilsComposition: About 5 percent

24 Soil Survey

Major Uses

Hay, livestock grazing, wildlife habitat

11—Badland

Map Unit Setting

Major Land Resource Area: 35Elevation: 6,500 to 8,000 feet (1,981 to 2,438 meters)Mean annual precipitation: 8 to 11 inches (203 to 279

millimeters)Average annual air temperature: 43 to 45 degrees F



Badland: 90 percentMinor components: 10 percent


Badland

Description: Badland is moderately steep toextremely steep barren lands dissected by manyintermittent drainage channels on erodeduplands. These areas are formed by activegeologic erosion of soft, multicolored,sedimentary beds consisting of shale andsandstone.

Slope: 10 to 120 percentDepth to restrictive feature: 0 to 3 inches to bedrock

(paralithic)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: Very highLand capability subclass (nonirrigated): 8e

Minor Components

Typic Torriorthents and similar soilsComposition: About 10 percentLandform: Drainageway

Major Uses

Wildlife habitat

12—Baird Hollow-Nordicol-Rymancomplex, 5 to 40 percent slopes

Map Unit Setting

Major Land Resource Area: 48AElevation: 8,800 to 10,000 feet (2,682 to

3,048 meters)

Mean annual precipitation: 24 to 26 inches (610 to660 millimeters)

Average annual air temperature: 35 to 37 degrees F(2 to 3 degrees C)

Frost-free period: 40 to 60 days


Baird Hollow and similar soils: 35 percentNordicol and similar soils: 25 percentRyman and similar soils: 20 percentMinor components: 20 percent


Baird Hollow soils

Landform: Mountain slopeParent material: Colluvium and residuum from

sandstone and shaleSlope: 5 to 40 percentDrainage class: Well drainedSlowest permeability: SlowAvailable water capacity: About 6.4 inches (moderate)Shrink-swell potential: About 4.5 percent (moderate)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: HighCalcium carbonate maximum: NoneEcological site: Spruce-FirPotential native vegetation: quaking aspen, elk

sedge, common juniper, dwarf blueberry,kinnikinnick, tufted hairgrass, Fendler’sceanothus, Oregongrape, boxleaf myrtle, noddingbrome


Typical profile:0 to 14 inches—stony loam14 to 28 inches—very cobbly sandy clay loam,

very stony clay loam28 to 40 inches—very stony clay loam40 to 44 inches—very stony clay44 to 60 inches—gravelly clay

Nordicol soils

Landform: Mountain slopeParent material: Colluvium and residuum weathered

from sandstoneSlope: 5 to 40 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 6.3 inches (moderate)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: None


Depth to seasonal high water table: Greater than 72inches

Runoff class: HighCalcium carbonate maximum: NoneEcological site: Spruce-FirPotential native vegetation: quaking aspen, slender

wheatgrass, elk sedge, Arizona fescue, Thurber’sfescue, blue wildrye, mountain brome, mountainsnowberry, nodding brome


Typical profile:0 to 15 inches—loam15 to 24 inches—gravelly sandy clay loam24 to 32 inches—very cobbly sandy clay loam32 to 48 inches—very cobbly sandy clay loam48 to 60 inches—very stony sandy clay loam

Ryman soils

Landform: Mountain slopeParent material: Residuum weathered from

interbedded sandstone and shaleSlope: 5 to 40 percentDrainage class: Well drainedSlowest permeability: SlowAvailable water capacity: About 9.2 inches (high)Shrink-swell potential: About 4.5 percent (moderate)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: Very highCalcium carbonate maximum: NoneEcological site: Quaking AspenPotential native vegetation: quaking aspen, slender

wheatgrass, elk sedge, slender wheatgrass,Arizona fescue, Thurber’s fescue, blue wildrye,mountain brome, mountain snowberry, noddingbrome


Typical profile:0 to 23 inches—clay loam23 to 27 inches—cobbly clay loam27 to 39 inches—cobbly clay, stony clay39 to 60 inches—cobbly clay

Minor Components

Nordicol Variant and similar soilsComposition: About 10 percent

Leaps and similar soilsComposition: About 5 percent

Adel and similar soilsComposition: About 5 percent

Major Uses

Livestock grazing in summer, wildlife habitat,timber products

13—Barkelew-Emmons complex, 5 to 40percent slopes

Map Unit Setting





Barkelew and similar soils: 50 percentEmmons and similar soils: 30 percentMinor components: 20 percent


Barkelew soils

Landform: MesaParent material: Till and colluvium from mixed

sourcesSlope: 5 to 40 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 5.9 inches (low)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: HighCalcium carbonate maximum: About 30 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Ecological site: Pinyon-JuniperPotential native vegetation: Utah juniper, twoneedle

pinyon, Gambel’s oak, muttongrass, Indianricegrass, elk sedge, Saskatoon serviceberry,true mountain mahogany

Potential production of cordwood: 15 to 20 cords peracre in a stand that averages 5 inches indiameter at a height of 1 foot


Typical profile:0 to 2 inches—very cobbly clay loam2 to 10 inches—cobbly clay loam

26 Soil Survey

Figure 4.—Irrigated alfalfa hay harvest. The soil is Barx fine sandy loam, 1 to 3 percent slopes.

10 to 22 inches—extremely stony clay loam22 to 60 inches—extremely stony loam

Emmons soils

Landform: MesaParent material: Till and colluvium from mixed

sourcesSlope: 5 to 20 percentDrainage class: Well drainedSlowest permeability: Moderately slowAvailable water capacity: About 9.9 inches (high)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: HighCalcium carbonate maximum: About 25 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Ecological site: Pinyon-JuniperPotential native vegetation: Utah juniper, twoneedle

pinyon, Gambel’s oak, muttongrass, Indianricegrass, elk sedge, Saskatoon serviceberry,true mountain mahogany

Potential production of cordwood: 15 to 20 cords per

acre in a stand that averages 5 inches indiameter at a height of 1 foot


Typical profile:0 to 5 inches—very cobbly loam5 to 15 inches—cobbly clay loam15 to 60 inches—cobbly clay loam

Minor Components

Wrayha and similar soilsComposition: About 10 percent

Ustochreptic Calciorthids and similar soilsComposition: About 10 percent

Major Uses

Livestock grazing, wildlife habitat

14—Barx fine sandy loam, 1 to 3 percentslopes

Map Unit Setting

Major Land Resource Area: 35 (fig. 4)


Elevation: 5,300 to 6,800 feet (1,615 to 2,073 meters)Mean annual precipitation: 10 to 14 inches (254 to




Barx and similar soils: 85 percentMinor components: 15 percent


Barx soils

Landform: Terrace, mesaParent material: Alluvium derived from sandstoneSlope: 1 to 3 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 9.4 inches (high)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: LowCalcium carbonate maximum: About 45 percentSalinity maximum: About 4 mmhos/cm (very slightly

saline)Sodicity maximum: Sodium adsorption ratio about 10

(slightly sodic)Ecological site: Semidesert Sandy LoamPotential native vegetation: Wyoming big sagebrush,

galleta, needleandthread, Indian ricegrass,western wheatgrass


Typical profile:0 to 2 inches—fine sandy loam2 to 23 inches—loam, sandy clay loam23 to 74 inches—loam

Minor Components

Abra and similar soilsComposition: About 7 percent


Nyswonger and similar soilsComposition: About 3 percentLandform: Drainageway

Major Uses

Livestock grazing, wildlife habitat, cropland


Map Unit Setting







Barx soils

Landform: Mesa, terraceParent material: Alluvium derived from sandstoneSlope: 3 to 6 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 9.4 inches (high)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than

72 inchesRunoff class: MediumCalcium carbonate maximum: About 45 percentSalinity maximum: About 4 mmhos/cm (very

slightly saline)Sodicity maximum: Sodium adsorption ratio about 10




Typical profile:0 to 2 inches—fine sandy loam2 to 23 inches—sandy clay loam, loam23 to 74 inches—loam

Minor Components



28 Soil Survey


Major Uses



Map Unit Setting







Barx soils

Landform: Mesa, terraceParent material: Alluvium derived from sandstoneSlope: 6 to 12 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 9.4 inches (high)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: MediumCalcium carbonate maximum: About 45 percentSalinity maximum: About 4 mmhos/cm (very slightly

saline)Sodicity maximum: Sodium adsorption ratio about 10





Minor Components




Major Uses


17—Barx-Progresso complex, 3 to 12percent slopes

Map Unit Setting





Barx and similar soils: 45 percentProgresso and similar soils: 40 percentMinor components: 15 percent


Barx soils

Landform: Mesa, old terraceParent material: Alluvium derived from sandstoneSlope: 3 to 12 percentDrainage class: Well drainedSlowest permeability: ModerateAvailable water capacity: About 9.4 inches (high)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than

72 inchesRunoff class: MediumCalcium carbonate maximum: About 45 percentSalinity maximum: About 4 mmhos/cm (very

slightly saline)Sodicity maximum: Sodium adsorption ratio about 10






Progresso soils

Landform: Mesa, old terraceParent material: Alluvium derived from sandstoneSlope: 3 to 12 percentDepth to restrictive feature: 20 to 40 inches to

bedrock (lithic)Drainage class: Well drainedSlowest permeability: Moderately slowAvailable water capacity: About 4.7 inches (low)Shrink-swell potential: About 4.5 percent (moderate)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: HighCalcium carbonate maximum: About 35 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Ecological site: Semidesert LoamPotential native vegetation: galleta, Indian ricegrass,

Wyoming big sagebrush, muttongrass, westernwheatgrass, rabbitbrush

Land capability subclass (nonirrigated): 6c

Typical profile:0 to 7 inches—loam7 to 14 inches—clay loam14 to 24 inches—clay loam24 to 36 inches—sandy loam36 to 40 inches—unweathered bedrock

Minor Components


Pinon and similar soilsComposition: About 5 percent

Bowdish and similar soilsComposition: About 3 percent

Rock outcropComposition: About 2 percent

Major Uses

Livestock grazing in spring and fall, wildlife habitat

18—Begay fine sandy loam, 1 to 6 percentslopes

Map Unit Setting

Major Land Resource Area: 35

Elevation: 4,900 to 6,200 feet (1,494 to 1,890 meters)Mean annual precipitation: 9 to 12 inches (229 to 305

millimeters)Average annual air temperature: 47 to 49 degrees F



Begay and similar soils: 85 percentMinor components: 15 percent


Begay soils

Landform: Old terraceParent material: Alluvium derived from sandstoneSlope: 1 to 6 percentDrainage class: Well drainedSlowest permeability: Moderately rapidAvailable water capacity: About 7.9 inches (moderate)Shrink-swell potential: About 1.5 percent (low)Hazard of flooding: NoneDepth to seasonal high water table: Greater than 72

inchesRunoff class: Very lowCalcium carbonate maximum: About 15 percentGypsum maximum: About 2 percentSalinity maximum: About 2 mmhos/cm (nonsaline)Sodicity maximum: Sodium adsorption ratio about 10

(slightly sodic)Ecological site: Semidesert Sandy LoamPotential native vegetation: galleta, Wyoming big

sagebrush, Indian ricegrass, needleandthread,blue grama, bottlebrush squirreltail, sanddropseed


Typical profile:0 to 3 inches—fine sandy loam3 to 12 inches—fine sandy loam12 to 60 inches—fine sandy loam

Minor Components

Barx and similar soils

Documents

Soil Survey of the San Miguel Area, Colorado...San Miguel Area, Colorado Parts of Dolores, Montrose, and San Miguel Counties United States Department of Agriculture Natural Resources