LOCATION MILLESON WY
Tentative Series
DPG/DJP/CBR
05/2020
MILLESON SERIES
The Milleson series consists of very deep, somewhat poorly drained soils that formed in alluvium derived from sandstone, shale, and interbedded sedimentary rock. These soils are on floodplains. Slopes are 0 to 2 percent. Mean annual precipitation is about 205 mm and mean annual air temperature is about 4.5 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Ustic Aquicambids
TYPICAL PEDON: Milleson sandy clay loam in irrigated hayland. (Colors are for moist soil unless otherwise noted.)
Oe--0 to 4 cm; moderately decomposed plant material; clear smooth boundary (0 to 8 cm thick).
A--4 to 18 cm; olive brown (2.5Y 4/3) sandy clay loam, light olive brown (2.5Y 5/3), dry; moderate medium subangular blocky structure; friable, slightly hard, moderately sticky, moderately plastic; many very fine and fine roots; many fine tubular pores; 20 percent dark yellowish brown (10YR 4/6) and dark grayish brown (10YR 4/2) redox concentrations; finely disseminated carbonate; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (4 to 10 cm thick)
Bk--18 to 25 cm; olive gray (5Y 5/2) sandy clay loam, light olive gray (5Y 6/2), dry; weak fine subangular blocky structure; friable, slightly hard, moderately sticky, moderately plastic; common very fine and fine roots; common fine tubular pores; 40 percent dark yellowish brown (10YR 4/6) and dark grayish brown (10YR 4/2) redox concentrations; finely disseminated carbonate; strongly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (7 to 40 cm thick)
BCk--25 to 65 cm; olive (5Y 5/3) sandy clay loam, pale olive (5Y 6/3), dry; weak fine subangular blocky structure; friable, slightly hard, moderately sticky, moderately plastic; many very fine and fine roots; many fine tubular pores; 35 percent dark yellowish brown (10YR 4/6) and dark grayish brown (10YR 4/2) redox concentrations; finely disseminated carbonate; strongly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (0 to 30 cm thick)
C1--65 to 85 cm; olive (5Y 5/3) fine sandy loam, pale olive (5Y 6/3), dry; massive; friable, slightly hard, slightly sticky, slightly plastic; 15 percent dark yellowish brown (10YR 4/6) and dark grayish brown (10YR 4/2) redox concentrations; finely disseminated carbonate; slightly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (20 to 60 cm thick)
C2--85 to 200 cm; olive (5Y 5/4) fine sandy loam, pale olive (5Y 6/4), dry; massive; friable, slightly hard, slightly sticky, slightly plastic; finely disseminated carbonate; strongly effervescent; moderately alkaline (pH 8.0).
TYPE LOCATION: Sublette County, Wyoming; USGS Milleson Draw, Wyoming topographic quadrangle; 42 degrees 27 minutes 22 seconds north latitude and 110 degrees 4 minutes 1 second west longitude, datum WGS84.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--3.5 to 8.0 degrees C
Depth to water table--45 to 90 cm
Particle-size control section (weighted averages):
Clay content--18 to 27 percent
Total rock fragments--0 to 5 percent
Oe (when present)
Texture--moderately decomposed plant material
Reaction--pH 4.0 to 5.5
Organic matter content--55 to 90 percent
A horizon
Hue--10YR to 5Y
Value--4 or 5
Chroma--2 to 4
Texture (less than 2 mm fraction)--sandy clay loam, loam
Clay content--18 to 30 percent
Rock fragments--0 to 5 percent gravel
Reaction--pH 7.9 to 8.4
Bk horizon
Hue--10YR to 5Y
Value--5 or 6 dry, 4 or 5 moist
Chroma--3 to 5 dry, 2 to 4 moist
Texture (less than 2 mm fraction)--sandy clay loam, loam
Clay content--18 to 30 percent
Rock fragments--0 to 5 percent gravel
Calcium carbonate equivalent--3 to 14 percent
Reaction--pH 7.9 to 8.4
BCk horizon (when present)
Hue--10YR to 5Y
Value--5 or 6 dry, 4 or 5 moist
Chroma--3 to 5 dry, 2 to 4 moist
Texture (less than 2 mm fraction)--sandy clay loam, loam
Clay content--18 to 30 percent
Rock fragments--0 to 5 percent gravel
Calcium carbonate equivalent--5 to 14 percent
Reaction--pH 7.9 to 8.4
C horizons
Hue--10YR to 5Y
Value--5 or 6 dry, 4 or 5 moist
Chroma--4 or 5 dry, 3 or 4 moist
Texture (less than 2 mm fraction)--fine sandy loam, sandy clay loam, loam
Clay content--13 to 25 percent
Rock fragments--0 to 5 percent gravel
Calcium carbonate equivalent--3 to 15 percent
Reaction--pH 7.9 to 8.4
COMPETING SERIES:
There are no competing series.
GEOGRAPHIC SETTING:
Landform--floodplains
Elevation--1,950 to 2,160 meters
Slope--0 to 2 percent
Parent material--alluvium derived from sandstone, shale, and interbedded sedimentary rock
Climate--long, cold winters; cool, moist springs; short, warm summers
Mean annual precipitation--175 to 250 mm
Mean annual air temperature--2.5 to 7.0 degrees C
Frost-free period--50 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: somewhat poorly drained, 5.0 to 15.0 um/sec
USE AND VEGETATION: Milleson soils are primarily used for irrigated pasture or hayland. The potential native vegetation is basin wildrye, Indian ricegrass, western wheatgrass, greasewood and other sedges, rushes, and forbs.
DISTRIBUTION AND EXTENT: Milleson soils are of small extent in western Wyoming; MLRA 34A.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Sublette County, Wyoming 2019. Milleson series is derived from a local landmark.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon--4 to 18 cm (A horizon)
Cambic horizon--18 to 65 cm (Bk and BCk horizons)
Redoximorphic features--4 to 85 cm (A, Bk, BCk, and C1 horizons)
Particle-size control section--29 to 104 cm
Milleson soils have a frigid temperature regime and an aridic moisture regime bordering on ustic.
Taxonomic version: Twelfth Edition, 2014
National Cooperative Soil Survey
U.S.A.