LOCATION ELLISTON MT
Established Series
Rev. BDD-JAL-KLS
03/2023
ELLISTON SERIES
The Elliston series consists of very deep, somewhat poorly drained soils that formed in loamy alluvium. These soils are on flood plains. Slopes are 0 to 4 percent. Mean annual precipitation is about 410 mm, and mean annual air temperature is about 6 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Aquic Haplustepts
TYPICAL PEDON: Elliston loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 3 cm; slightly decomposed forest litter.
A--3 to 21 cm; light brownish gray (10YR 6/2) loam, grayish brown (10YR 5/2) moist; strong medium granular structure; slightly hard, friable, nonsticky and slightly plastic; many very fine, fine and few coarse roots; many very fine and fine interstitial pores; moderately alkaline (pH 8.0); clear smooth boundary. (8 to 20 cm thick)
Bw--21 to 34 cm; pale brown (10YR 6/3) loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; many fine and very fine roots; many very fine and fine interstitial pores; slightly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (8 to 15 cm thick)
Bk--34 to 115 cm; light gray (10YR 7/2) loam, grayish brown (10YR 5/2) moist; many fine distinct yellowish red (5YR 5/8) redox concentrations; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine interstitial pores; finely disseminated carbonates, few fine masses of carbonates; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (20 to 84 cm thick)
2C--115 to 156 cm; light gray (10YR 7/2) very gravelly loam, grayish brown (10YR 5/2) moist; many fine distinct yellowish red (5YR 5/8) redox concentrations; massive; soft, friable, slightly sticky and nonplastic; few fine roots; many very fine and fine interstitial pores; 40 percent gravel; strongly effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Powell County, Montana; about 365 meters west and 790 meters south of the NE corner of Sec. 26, T. 14 N., R. 11 W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--4 to 8 degrees C
Soil moisture control section--10 to 30 cm
Depth to horizon of secondary calcium carbonate accumulation--15 to 60 cm
Depth to seasonal high water table--60 to 100 cm
A horizon
Value--4 or 5 moist
Chroma--2 or 3
Clay content--18 to 27 percent
Rock fragment content--0 to 10 percent gravel
Reaction--pH 7.9 to 8.4
Bw horizon
Value--5 or 6 dry; 3 or 4 moist
Clay content--18 to 27 percent
Rock fragment content--0 to 10 percent gravel
Reaction--pH 7.9 to 8.4
Bk horizon
Value--6 or 7 dry; 4 or 5 moist
Chroma--2 or 3
Clay content--18 to 27 percent
Rock fragment content--0 to 20 percent total; 0 to 10 percent gravel and 0 to 10 percent cobbles
Calcium carbonate equivalent--5 to 15 percent
Reaction--pH 7.9 to 8.4
2C horizon
Value--5, 6 or 7 dry; 4 or 5 moist
Chroma--2 or 3
Texture--loam or sandy loam
Clay content--8 to 20 percent
Rock fragment content--35 to 60 percent total; 35 to 50 percent gravel and 0 to 10 percent cobbles
Reaction--7.9 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform--flood plains
Elevation--1150 to 1525 meters
Slope--0 to 4 percent
Parent material--loamy alluvium
Climate--cool with long, cold winters; moist springs and falls; warm, dry summers
Mean annual precipitation--380 to 480 mm
Mean annual air temperature--3 to 7 degrees C
Frost-free period--70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderate permeability.
USE AND VEGETATION: Elliston soils are used for irrigated and nonirrigated pasture, and for timber production. Native timber species are Engelman spruce, ponderosa pine, Rocky Mountain Juniper, plains cottonwood, and quaking aspen with an understory of common snowberry, woods rose, basin wildrye, prairie cordgrass, bearded wheatgrass, Rocky Mountain Iris, willows, and water birch.
DISTRIBUTION AND EXTENT: Elliston soils are of small extent in the mountain valleys of western Montana; MLRAs 43B and 44B.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Powell County, Montana, 1995
REMARKS: Soil interpretation record: MT1238
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--3 to 21 cm (A horizon)
Cambic horizon--21 to 34 cm (Bw horizon)
Horizon with secondary calcium carbonate accumulation--34 to 115 cm (Bk horizon)
Particle-size control section--25 to 100 cm (part of the Bw and Bk horizons)
Elliston soils have a frigid temperature regime and an ustic soil moisture regime.
Converted to metric and O horizons were updated to start at zero. Competing series section was not updated. 01/2023
National Cooperative Soil Survey
U.S.A.