WILLIAMSON RIVER ROAD

LONE PINE ROAD

US-9

7

OR-140 OR-140

SPRAGUE RIVER ROAD

SPRAGUE RIVER ROAD

SQUAW FLAT ROAD

SPRAGUE RIVER ROAD

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KamkaunSpring

WhitehorseSpring

McReadySpring

LaloSpring

MedicineSprings

BrownSpring

Chiloquin

Sprague River

Beatty

Bly

Braymill

11501000

11499100

11497500

11495600

Will

iam

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Rive

r

CopperfieldDraw

Trout Creek

North Fork Trout Creek

Whisky Creek

South Fork TroutCr

eek

Snake Creek

Fivemile Creek

Long

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Cree

k

Fritz Creek

Deming

Creek

FishholeCreek

Paradise Creek

CampbellReservoir

Wild BillyLake

HawksLake

Sprague

River

NorthFork Sprague River

SpragueRiver

SycanRiver

Dockn

eyCree

k

Rock

Cree

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BrownCreek

SouthFork

SpragueRiver

Spragu

eRi

ver

Spragu

eRi

ver

FORMERCHILOQUIN

DAM

7/1/05-17/1/05-2

7/2/05-1

9/14/07-1

6/26/07-3

9/12/06-2, 3

6/25/07-1, 2 6/28/07-1

6/22/07-4, 5

7/24/07-1, 2

6/23/07-1

9/13/06-1, 29/13/06-3

9/13/07-3

6/28/05-1

9/20/06-4, 59/15/06-2

9/15/06-1a, b

6/28/07-2

9/12/06-1a

9/20/06-1,2, 3

9/22/05-1, 29/22/05-3, 4

7/1/05-17/1/05-2

7/2/05-1

9/14/07-1

6/26/07-3

9/12/06-2, 3

6/25/07-1, 2 6/28/07-1

6/22/07-4, 5

7/24/07-1, 2

6/23/07-1

9/13/06-1, 29/13/06-3

9/13/07-3

6/28/05-1

9/20/06-4, 59/15/06-2

9/15/06-1a, b

6/28/07-2

9/12/06-1a

9/20/06-1,2, 3

9/22/05-1, 29/22/05-3, 4

Saddle Mountain

Knot Tableland

RoundMountain

Cliney

Flat

FergusonMountain

MedicineMountain

CouncilButte

SpringButte

BugButte

Cave

M

ount

ain

Bad Lands

Buttes of the Gods

Switchback Hill

Bly Mountain

K Davis Hill

Bly Ridge

Devil’sGarden

Beatty Gap

S’Ocholis Canyon

Sycan Canyon

Knot Tableland

121°50’

121°40’

121°30’ 121°20’ 121°10’

121°00’

121°50’

121°40’

121°30’

121°20’

121°10’

121°

42°35’

42°30’

42°25’

42°25’

42°30’

42°35’

42°20’

SCALE 1:100,000

0 2 4 6 8 10 MILES

0 2 4 6 8 10 KILOMETERS

Water—Located outside mapped area. From National Hydrography Dataset

Primary channel—Mapped from 2000 aerial photographs

Contact

Flood-plain transects—Spaced every 1 kilometer, labeled every 5 kilometers starting from mouth of river or tributary

Sprague basin boundary

Streams—From National Hydrography Dataset. Not displayed within geomorphic flood plain

Road Major (highway) Minor

EXPLANATION

6-28-07-2

35

Stratigraphy site—With site number(s) Click to view cross section

Former dam site

Spring

Stream gage U.S. Geological Survey Oregon Water Resources Department

Town

ChiloquinCanyon

Braymill

KamkaunSpring

S’OcholisCanyon

Buttes ofthe Gods

Council Butte BeattySycan

LowerSycan

CoyoteButte

Beatty Gap UpperValley South

Fork

NorthFork

0

11.4

17.2

32.4

48.2

58.0

76.8

81.0 89.6 93.2

106.3

00

10.6

9.8

Geomorphic Flood Plain Study Reaches

Sprague River basinStudy area

OREGON

Portland

Klamath Falls

Geomorphic Flood Plain (Holocene)—Area of Holocene channel migration; channels and active flood plains along the North Fork Sprague, South Fork Sprague, main-stem Sprague, and Sycan Rivers. This map unit, divided into valley segments, is the domain of the detailed mapping analysis of constructed features, historical channel change, and vegetation described in this report. This unit encompasses the area of channels, abandoned channels, and bar-and-scroll topography evident on the 2004 LiDAR. The presence of main-stem channel topographic features distinguishes this unit from the valley fill unit. Soils are typically poorly drained and include volcanic-ash-rich Mollisols dominated by the Klamath-Ontko-Dilman series (Cahoon, 1985). Stratigra-phy exposed on eroding streambanks and from augering show that these flood-plain deposits almost everywhere formed after the 7.7 ka (kilo-annum, thousands of calendar years before present) Mazama eruption. In places, particularly along the lower Sycan River (Lind, 2009) and the North Fork Sprague River, stratigraphic relations show at least two episodes of flood-plain erosion and rebuilding in the last 7.7 ka. The geomorphic flood plain has formed in the last 7.7 ka from a combination of channel migration, channel avulsion, and lateral and vertical accretion of bedload and suspended load deposits. The geomorphic flood plain is mapped on the basis of morphology and does not necessarily correspond to a specific elevation above the channel or areas subject to flooding at a specific frequency. Locally includes springs and associated wetland deposits within the area of Holocene channel migration.

Main-Stem Valley Fill (Holocene)—Flood plain and basin areas outside of active channel areas but historically subject to overbank flooding. Low-gradient planar surfaces totaling 28 km2 (square kilometers) occupy broad areas flanking the Sprague River corridor, particularly in the Kamkaun Springs, S'Ocholis Canyon, and Buttes of the God valley segments. Additionally, this map unit includes bottomlands flanking the post-Mazama (7.7 ka) zone of channel migration (the Active Main-stem Flood plain) in the Council Butte and Beatty-Sycan valley segments. The surfaces generally have soils mapped as Inceptisols or Mollisols formed in part by cumulic deposition of silt and clay during overbank flooding. Many of the surfaces are flooded during periods of high water, but show no evidence of hosting major channels. Many of these surfaces are now diked and drained. Some of these broad valley bottoms marginal to the main river course, especially within the Kamkaun Springs, S'Ocholis Canyon and Buttes of the God valley segments, appear to be long-term sediment depocenters as a consequence of overall Sprague River valley aggradation, perhaps in conjunction with block faulting along the north-northwest trending faults transecting the lower part of the Sprague River valley. Within the Council Butte and Beatty-Sycan valley segments, the valley fill unit encompasses broad tracts of seasonally inundated lowlands flanking the Sprague River, but outside areas occupied by late Holocene channels. In places, this unit may correspond with low terraces mapped in the Council Buttes and Beatty Gap valley segments.

Terrace (Quaternary)—Terrace deposits along main-stem Sprague River. Planar alluvial surfaces as high as 50 m (meters) above the active flood plain flank the Sprague River near its confluence with the Williamson River. Similarly, terraces at several elevations ranging up to 20 m above the geomorphic flood plain border the Sprague River in the Chiloquin Canyon, Braymill, Kamkaun Spring, S'Ocholis Canyon, and Buttes of the Gods valley segments. Locally, terraces are enumerated 1 through 4 on the basis of increasing elevation (and presumably age) above the geomorphic flood plain. Isolated low terraces flank the Sprague River in the Council Butte and Beatty Gap segments, as well as along the lower Sycan River. The terrace surfaces are underlain by fluvial gravel and are generally stable features upon which Haploxeroll soils have formed, indicating formation of a cambic B horizon and some carbonate accumulation (Cahoon, 1985). Terrace risers locally expose Tertiary lacustrine sediment or other bedrock units, indicating that at least some of the terraces are strath surfaces cut into the soft Tertiary sediment. The positions and degree of soil development are consistent with ages of late Tertiary through Quaternary. Many or all of these terraces pre-date the 7.7 ka Mazama eruption, judging from the presence of Mazama fall-out tephra in the upper parts of their soil profiles (Cahoon, 1985). Like the abandoned alluvial fans, the terraces result from episodic filling and incision during Quaternary downcutting of the Sprague River. Some of this downcutting may have resulted from broadscale base-level fall associated with integration of the upper Klamath River basin (Sherrod and Pickthorn, 1992), but some terrace sequences may reflect more local tectonic blockages associated with the north-northwest trending basin-and-range faulting affecting the western Sprague River valley segments.

Active Tributary Flood Plain (Holocene)—Tributary channel, flood plain, and basin fill deposits in low-gradient areas subject to inundation, and unconfined by valley margins. Tributary channels and flanking surfaces grade to modern main-stem channels and flood plains, forming narrow and elongate map units extending into the uplands where channels become increasingly topographically confined. In some reaches, especially the Kamkaun Springs, the tributary valleys have very low, nearly horizontal, gradients, whereas in many locations, tributary valley flood plains have gradients approaching 5 degrees. The distinction with tributary fans and colluvium is primarily on the basis of plan-view morphology and slope but is locally indistinct. Primary soils on tributary flood plains are Inceptisols and Mollisols, which typically form in late Pleistocene or Holocene deposits (Cahoon, 1985).

Active Tributary Fans (Quaternary)—Shallowly sloping (less than 10 degrees) alluvial transport surfaces grading to modern main-stem and tributary flood plains, commonly with a singular or composite fan-shaped down-gradient terminus. These are active alluvial transport surfaces heading from confined tributaries, colluvial slopes and bedrock, and have formed where flow routes expand onto flat terraces, flood plains and other flat bottomland surfaces. These surfaces are commonly gradational with colluvial slopes and valley bottomlands, but with intermediate slopes. Active fan surfaces are mantled with Haploxerolls, Cryorthents, Cryofluvents, Cryoborolls, and Cryaquepts soil taxonomic classes, all of which have only incipient horizon develop-ment in the form of translocated and accumulated carbonates and silica, consistent with late Pleistocene to Holocene ages. Many active fans have surfaces post-dating the 7.7 ka Mazama eruption. Active fans episodically provide sediment to the main-stem rivers and flood plains.

Abandoned Fan (Quaternary/Tertiary)—Incised tributary fan deposits, surfaces as much as 30 m above active channels. These shallowly sloping (less than 10 degrees) alluvial transport surfaces have been incised because of base-level fall. Large abandoned fan complexes border the southern Sprague River valley in the Buttes of the Gods and Council Butte valley segments. Constriction of the valley by one such fan near the settlement of Sprague River separates these two valley segments. Locally, abandoned fan surfaces are enumerated 1 through 4 on the basis of increasing degree of incision (and presumably age). The older surfaces have only isolated remnants of original transport surfaces, underlain by fluvial gravel, separated by younger (and lower) fan and tributary surfaces and by slopes formed in the underlying Tertiary lacustrine sediment. Some abandoned fan surfaces, including those south of the Sprague River valley near Beatty and Bly, are partly formed of pumiceous pyroclastic flow deposits derived from Tertiary volcanic centers to the south (Sherrod and Pickthorn, 1992). Near the Sprague and Sycan Rivers, these tributary fan deposits are locally interbedded with main-stem fluvial channel and overbank deposits. Primary soil taxonomic classes on abandoned fan surfaces include Haploxerolls, Argixerolls, and Durixerolls, indicating minor to significant accumula-tions of clays, silica, and carbonate. The ages of these surfaces likely range from Pliocene to possibly as young as early Holocene. All abandoned fan deposits, however, likely post-date the approximately 3.0 Ma (Mega-annum; million years) Basalt of Knot Tableland. The abandoned fans are largely stable features that contribute little sediment directly to the modern fluvial system. These abandoned alluvial fans reflect overall Tertiary and Quaternary valley incision of the Sprague River valley, probably in conjunction with integration and incision of the Sprague River through fault-uplifted canyon segments downstream.

Active Springs and Spring Deposits (Holocene)—Active springs and associated wetland deposits. Six areas of springs and related features such as ponds, wetlands, and channels are within the map area but outside of main-stem flood plains. Most are contiguous with the main-stem flood plain or flanking terraces. Spring outlets with flowing water have sandy to gravel substrates, surrounding areas consisting chiefly of saturated peat deposits formed from aquatic vegetation. Most spring complexes are connected to the Sprague and Sycan Rivers by sand-bed spring channels.

Sycan Flood Deposits (Holocene)—A prominent planar surface extending south discontinuously from the lower Sycan River canyon to its confluence with the Sprague River. This surface stands 3 m above the active flood plain at the downstream end of Sycan Canyon, and descends to flood plain level near the Sycan River confluence with the Sprague River. It is underlain by as much as 3.35 m of bedded sand and gravel composed almost entirely of Mazama pumice. The deposits fine and thin downstream, where they are overlain by alternating beds of silty fine sand and sand. At their apex near the downstream end of the Sycan Canyon, these deposits grade to surfaces mantled with 1-m-diameter rounded basalt boulders, apparently derived from the canyon rim and walls and transported downstream. The soil capping these surfaces is mainly classified as an Ashy Typic Cryopsamment, indicating poorly developed soils formed in sandy parent materials. The pumiceous sand and gravel overlies organic-rich silt and clay deposits, locally peaty, and commonly containing within 10 cm of its top, a 0.5-to-2.5-cm-thick layer of silt- and sand-size Mazama tephra. This fallout tephra, constrained by radiocarbon dates here and in other areas, resulted from the Mazama eruption of about 7.7 ka. We infer that this terrace resulted from a large, pumice-laden flood down the Sycan River within a few decades or centuries of the 7.7 ka Mazama eruption. A plausible source for such a flood was temporary impound-ment of a lake in the Sycan Marsh area, possibly by dunes of Mazama pumice blocking the Sycan River channel near the marsh outlet (Lind, 2009). The Sycan flood deposits are coarse, loose, and erode readily from disturbed sites, particularly along tall banks flanking the modern channel or flood plain.

Pond and Wetland Deposits (Holocene)—Lacustrine deposits associated with modern or historic waterbodies; only shown outside of active flood plain. Several small closed depressions host seasonal to perennial waterbodies. Most are within areas of valley fill or occupy depressions within abandoned alluvial fans. Nearly all are utilized for water storage with dikes or small dams augmenting storage capacity.

Colluvial Slopes (Quaternary)—Hillslope colluvium and piedmont slope deposits. Steep but smooth slopes, up to about 35 degrees, underlain by unconsolidated regolith and formed by gravitational and alluvial transport processes such as rockfall, avalanching, biogenic disturbance, and sheet wash transport. Colluvial slopes typically head at steep bedrock outcrops, which are the source of material, and transition downslope to alluvial transport surfaces. Colluvium is locally an important source of coarse (gravel-size) material to the Sprague and Sycan Rivers, especially in canyon segments where much of the flood plain is bordered by colluvium or bedrock. The distinction of colluvial slopes and active tributary fans is locally arbitrary, but tributary fans typically have slopes less than 10 degrees.

Landslide Deposits (Quaternary)—Deposits of large mass movements, primarily rotational failures, usually with steep hummocky topography bounded on upslope margins by arcuate scarps. A few landslides are evident in the Chiloquin Canyon valley segment and in the lowermost portion of the Sycan River canyon within the Coyote Bucket valley segment. The Sycan River canyon landslides likely blocked the channel, and the affected reaches traverse accumulations of large blocks of volcanic rock from the canyon rim.

Undifferentiated Bedrock (Tertiary)—Irregular, typically hummocky or steep topography, underlain by Tertiary lacustrine sediment or volcanic rocks. This unit was only mapped where completely surrounded by mapped alluvial or colluvial surfaces.

DESCRIPTION OF MAPPING UNIT

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GEOMORPHIC SURFACES OF THE SPRAGUE AND LOWER SYCAN RIVERS, OREGONBy

Jim E. O’Connor, Patricia F. McDowell, Pollyanna Lind, and Christine G. Rasmussen2012

Base compiled from U.S. Geological Survey digital data, includes:**Lidar details**(USGS or DOGAMI?), 1-meter resolution (along valley floor)U.S. Geological Survey digital data, 10-meter resolution (outside valley floor)Projection: Universal Transverse Mercator projection, Zone 10N, 1983 North American Datum

Geologic linework was digitized at a scale of 1:3,000 but the accuracyof the contacts varies depending on location and geologic unit.

U.S. DEPARTMENT OF THE INTERIORU.S. GEOLOGICAL SURVEY

SCIENTIFIC INVESIGATIONS REPORT ####Quaternary units in Sprague River valley, Oregon—PLATE 1

O’Connor and others, 2012, Channel and Flood plainProcesses in the Sprague and Sycan Rivers, Oregon

Prepared in cooperation withTHE UNIVERSITY OF OREGON AND U.S. FISH AND WILDLIFE SERVICE