LOCATION YEOMAN MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Pachic Haplustolls
TYPICAL PEDON: Yeoman silt loam. (Colors are of the dry soil unless otherwise stated).
Ap--0 to 10 inches; very dark grayish brown (10YR 3/2) silt loam, very dark brown (10YR 2/2) moist; moderate very fine granular structure; soft, very friable; high in organic matter; moderately acid (pH 6.0); abrupt lower boundary. (6 to 10 inches thick)
A2--10 to 16 inches; dark brown (7.5YR 3/2) silt loam; very dark brown (7.5YR 2.5/2) moist; weak very coarse prismatic and moderate very fine granular structure; soft, very friable; slightly acid (pH 6.5), clear lower boundary. (5 to 9 inches thick)
Bw--16 to 26 inches; light brown (7.5YR 6/3) gravelly loam, brown (7.5YR 4/3) moist; weak coarse prismatic structure parting to moderate fine blocky; soft, friable; noncalcareous; neutral (pH 7.0), clear lower boundary. (8 to 15 inches thick)
Bk--26 to 34 + inches; very pale brown (10YR 8/2) gravelly and stony silt loam, pale brown (10YR 6/3) moist; massive in place but separates to weak fine subangular blocks or lumps when disturbed; calcareous including abundant fine floury lime segregation. (12 to 16 inches thick)
TYPE LOCATION: Flathead County, Montana, SW1/4 of NE1/4 of Sec. 28, T29N, R20W.
RANGE IN CHARACTERISTICS: Silt loam, gravelly loam and stony loam types are recognized. The depth to the Bk ranges from 22 to about 36 inches. Under recent forest encrouchment and where there is open stands of large trees, the A1 tends to lose its brownish color and becomes dark gray, dry, and black, moist (chroma 1).
The Bw horizon colors have a hue range of 10YR and 7.5YR with chroma 3 to 4 in the former and mostly 3 in the latter. Where deepest, a B3 usually lies below the Bw.
COMPETING SERIES: These are the ARNEGARD, BEMAN, BOWERY, FALKIRK, GARLIPS, GARZA, LONECONE, MOLINARO, ROSEGLEN, SHAWA, and SHECKLE series.
GEOGRAPHIC SETTING: Undulating to steeply sloping moraines in the valleys and on the valley sides or mountain footslopes.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow, except medium on the steeper slopes; moderately permeable.
USE AND VEGETATION: Nonstony types largely are farmed, small grains and alfalfa being the principal crops. Stony areas remain in pasture. Mixed grasses common to the region. Single trees, thin stands and small patches of dense stands of Ponderosa pine and some larch in areas along the border of heavily forested areas of other soils.
DISTRIBUTION AND EXTENT: Western Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Upper Flathead Valley Area, Montana, 1957.