LOCATION YREKA MT
Established Series
Rev. HAL-BDD-RJS
05/2013
YREKA SERIES
The Yreka series consists of very deep, well drained soils that formed in colluvium and till derived from mixed rock sources. These soils are on alluvial fans, ridges, mountains, hills, and moraines. Slopes are 4 to 80 percent. Mean annual precipitation is about 560 mm, and mean annual air temperature is about 4.5 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Haplustalfs
TYPICAL PEDON: Yreka gravelly loam, forested, colors are for dry colors unless otherwise noted.
Oi--to 5 cm; partially decomposed twigs and needles. (2 to 8 cm thick)
E--5 to 36 cm; light brownish gray (10YR 6/2) gravelly loam, brown (10YR 5/3) moist; strong medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine, and common medium roots; many very fine and fine pores; 20 percent gravel, 5 percent cobbles; neutral; clear smooth boundary. (10 to 32 cm thick)
E/Bt--36 to 50 cm; E part (60 percent) is light brownish gray (10YR 6/2) very gravelly loam, brown (10YR 5/3) moist; Bt part (40 percent) is brown (10YR 5/3) very gravelly loam, brown (10YR 4/3) moist; moderate medium granular structure; slightly hard, friable, nonsticky and nonplastic; common very fine, fine and medium, and few coarse roots; 25 percent gravel, 10 percent cobbles; neutral; clear smooth boundary. (10 to 25 cm thick)
Bt--50 to 152 cm; brown (10YR 5/3) very gravelly clay loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine, medium and coarse roots; common very fine and fine pores; few faint clay films on faces of peds; 35 percent gravel, 10 percent cobbles; neutral.
TYPE LOCATION: Powell County, Montana; 90 meters south and 170 meters east of the NW corner of sec. 30, T. 11 N., R. 10 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 3.5 to 7.5 degrees C.
Depth to argillic horizon - 22 to 60 cm
Note: Some pedons may have an A horizon above the E horizon. Some pedons may also have a C horizon at depths greater than 100 cm.
E horizon
Hue: 10YR or 7.5YR; dry or moist
Value: 5 to 7 dry; 4 or 5 moist
Chroma: 2 or 3; dry or moist
Texture: loam, sandy clay loam or coarse sandy loam
Clay content: 7 to 27 percent
Rock fragments: 15 to 60 percent--15 to 35 percent gravel, 0 to 25 percent cobbles and stones
Reaction: pH 5.6 to 7.3
E/Bt horizon
Hue: 10YR or 7.5YR; dry or moist
Value: E part 6 or 7 dry, 5 or 6 moist; B part 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 4; dry or moist
Texture: clay loam, loam or sandy loam (mixed)
Clay content: 10 to 32 percent (mixed)
Rock fragments: 15 to 40 percent--15 to 35 percent gravel, 0 to 10 percent cobbles and stones
Reaction: pH 5.6 to 7.3
Bt horizon
Hue: 2.5Y, 10YR or 7.5YR; dry or moist
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 4; dry or moist
Texture: loam, clay loam or sandy clay loam
Clay content: 18 to 35 percent
Rock fragments: 35 to 60 percent--25 to 40 percent gravel, 0 to 25 percent cobbles and stones
Reaction: pH 5.6 to 7.3
C horizon (Where present)
Hue: 2.5Y, 10YR or 7.5YR; dry or moist
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 3; dry or moist
Texture: loam, sandy clay loam or sandy loam
Clay content: 10 to 25 percent
Rock fragments: 35 to 60 percent--25 to 45 percent gravel, 0 to 25 percent cobbles and stones
Reaction: pH 5.6 to 7.3
COMPETING SERIES:
Colomex (NM) - do not have an E/Bt horizon
Laventana (NM) - do not have an E/Bt horizon
Macmeal (MT) - have secondary calcium carbonate accumulation
Mocmont (MT) - have a glossic horizon
Namon (UT) - are deep to a lithic contact
Security (CO) - are moderately deep to a paralithic contact
Sheek (CO) - do not have an E/Bt horizon
Skyview (MT) - are moderately deep to a paralithic and lithic contact
Sonsela (NM) - do not have an E/Bt horizon
Tecolote (CO) - do not have an E/Bt horizon
Towaoc (CO) - do not have an E/Bt horizon
Trapps (MT) - have secondary calcium carbonate accumulation
Vision (MT) - do not have an E/Bt horizon
Wahatoya (CO) - are moderately deep to a lithic contact
Xankey (NM) - do not have an E/Bt horizon
Ymark (MT) - are deep to a paralithic and lithic contact
Yourame (MT) - have secondary calcium carbonate accumulation
GEOGRAPHIC SETTING:
Landform - alluvial fans, ridges, mountains, hills, and moraines
Elevation - 1,100 to 2,100 meters
Slopes - 4 to 80 percent
Parent material - colluvium and till derived from mixed rock sources
Climate - long, cold winters; moist springs
Mean annual precipitation - 380 to 635 cm, much of which falls as snow or as spring rain
Mean annual temperature - 2.5 to 5.5 degrees C.
Frost-free period - 70 to 105 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained, moderately slow permeability.
USE AND VEGETATION: Yreka soils are used for timber production, understory grazing, watersheds, and as wildlife habitat. The native vegetation is Douglas fir and ponderosa pine with an understory of common snowberry, pinegrass, and white spiraea.
DISTRIBUTION AND EXTENT: Yreka soils are of small extent in western Montana. MLRAs - 43B, 44A, 44B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Powell County, Montana, 1995.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 36 cm (Oi, E horizons)
Argillic horizon - from 36 to 152 cm (E/Bt, Bt horizons)
Particle-size control - from 36 to 86 cm (E/Bt, part of Bt horizon).
Yreka soils have a frigid temperature regime and an ustic moisture regime.
Additional Information: Soil interpretation record - MT1373.
National Cooperative Soil Survey
U.S.A.