LOCATION YELLOWBAY MTEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, frigid Typic Haploxerepts
TYPICAL PEDON: Yellowbay very gravelly loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 1 inch; partially decomposed needles, twigs, and grass; neutral (pH 6.6). (0 to 2 inches thick)
A--1 to 4 inches; dark grayish brown (10YR 4/2) very gravelly loam, very dark brown (10YR 2/2) moist; weak fine granular structure; soft, very friable, slightly sticky and nonplastic; many fine and medium roots; many fine and medium pores; 35 percent pebbles; neutral (pH 6.6); clear irregular boundary. (2 to 4 inches thick)
Bw--4 to 23 inches; yellowish brown (10YR 5/4) extremely gravelly sandy loam, brown (10YR 4/3) moist; massive; soft, friable, nonsticky and nonplastic; many fine and medium roots; many fine and medium pores; 60 percent pebbles and 5 percent cobbles; neutral (pH 6.6); gradual boundary. (15 to 25 inches)
BC--23 to 60 inches; brown (10YR 5/3) extremely gravelly loamy sand, brown (10YR 4/3) moist; single grain; loose, nonsticky and nonplastic; common fine and medium roots in upper part of horizon, few below; common fine pores; 60 percent pebbles; 5 percent cobbles; neutral (pH 6.6).
TYPE LOCATION: Lake County, Montana; 1,250 feet east and 400 feet north of the SW corner of sec. 18, T. 23 N., R. 19 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 47 degrees F.
Moisture control section - between 12 and 35 inches.
Control section - less than 35 percent medium and coarser sand.
Depth to BC horizon - 17 to 26 inches.
A horizon - Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Clay content: 7 to 15 percent
Rock fragments: 15 to 45 percent--0 to 10 percent cobbles, 15 to 35 percent pebbles
Reaction: pH 5.6 to 7.3
Bw horizon - Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4
Clay content: 5 to 10 percent
Rock fragments: 45 to 75 percent--5 to 10 percent cobbles, 40 to 65 percent pebbles
Reaction: pH 5.6 to 7.3
BC horizon - Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4
Clay content: 2 to 5 percent
Rock fragments: 55 to 80 percent--5 to 10 percent cobbles, 45 to 70 percent pebbles
Reaction: pH 5.6 to 7.3
COMPETING SERIES:
Wagontown (ID) - have a lithic contact between 40 and 60 inches; have more than 35 percent medium and coarse sand.
Watony (WA) - have more than 35 percent medium and coarser sand.
GEOGRAPHIC SETTING:
Landform - dissected alluvial fans, outwash plains, hills, escarpments and stream terraces.
Elevation - 2,300 to 4,000 feet.
Slope - 0 to 30 percent.
Parent material - glacial outwash or alluvium.
Climate - long, cold winters; moist springs and falls; warm, dry summers.
Mean annual precipitation - 15 to 25 inches, most of which falls as snow or as rain late in fall and early in spring.
Mean annual temperature - 39 to 45 degrees F.
Frost-free period - 90 to 120 days.
DRAINAGE AND PERMEABILITY: Excessively drained; moderately rapid permeability to a depth of 22 inches and rapid below.
USE AND VEGETATION: Yellowbay soils are used as woodland, for orchards, and as pastureland. Potential native vegetation is mainly ponderosa pine and Douglas fir in the overstory with an understory mainly of pinegrass, snowberry, mallow ninebark, and kinnikinnick.
DISTRIBUTION AND EXTENT: Yellowbay soils are of small extent in the northwestern valleys and foothills of Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lake County, Montana, 1991; proposed in Lake County, Montana, 1979. Yellowbay is a place name.
REMARKS: Soil interpretation records: MT0553, MT7041. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from 1 to 8 inches (A, part of Bw horizon); a cambic horizon from 4 to 23 inches (Bw horizon); a particle-size control section from 11 to 41 inches (Bw, BC horizons). Yellowbay soils have a frigid temperature regime and a xeric moisture regime.