LOCATION TRUDE ID+COEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed Xeric Dystrocryepts
TYPICAL PEDON: Trude gravelly loam, rangeland - on a 2 percent slightly convex south-facing slope. (When described on July 10, 1978, the soil was dry throughout. Colors are for air-dry soil unless otherwise stated.)
A--0 to 5 inches; yellowish brown (10YR 5/4) gravelly loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine roots; 15 percent gravel; neutral (pH 6.8); abrupt wavy boundary. (4 to 8 inches thick)
Bw1--5 to 12 inches; yellowish brown (10YR 5/4) gravelly loam, dark yellowish brown (10YR 3/4) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine roots; 15 percent gravel and 5 percent cobbles; neutral (pH 6.8); clear wavy boundary. (0 to 7 inches thick)
Bw2--12 to 17 inches; yellowish brown (10YR 5/4) very gravelly coarse sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine roots; 40 percent gravel and 15 percent cobbles; neutral (pH 6.6); gradual wavy boundary. (4 to 18 inches thick)
Bw3--17 to 25 inches; yellowish brown (10YR 5/4) very gravelly loamy coarse sand, dark yellowish brown (10YR 3/4) moist; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine roots; 35 percent gravel and 15 percent cobbles; neutral (pH 6.9); clear wavy boundary. (5 to 10 inches thick)
C--25 to 60 inches; variegated very gravelly coarse sand; single grain; loose; 40 percent gravel and 10 percent cobbles; neutral (pH 6.9).
TYPE LOCATION: Fremont County, Idaho; about 1 3/4 miles south and 1 3/4 miles east of Island Park Siding; 1,350 feet north and 1,815 feet west of the SE corner of section 17, T.12N., R.44E.
RANGE IN CHARACTERISTICS:
Depth to sand and gravel - 20 to 36 inches
Base saturation - 30 to 50 percent
Reaction - neutral to moderately acid
Average annual soil temperature - 38 to 40 degrees F.
Average summer soil temperature - 53 to 56 degrees F.
Moisture control section - between 12 and 36 inches; dry throughout the moisture control section for 60 to 100 consecutive days during the four months following the summer solstice
Rock fragments in the particle-size control section - average 35 to 60 percent.
A horizon
Value - 4 through 6 dry, 2 or 3 moist
Chroma - 3 or 4 dry or moist
Rock fragment content - 0 to 40 percent
Bw horizon
Value - 5 or 6 dry, 2 through 4 moist
Chroma - 3 or 4 dry or moist
Texture - GR-L, GRV-COSL, GR-COSL,or GRV-LCOS
Rock fragment content - 15 to 55 percent
C horizon
Texture - Stratified COS to GRX-COS
Rock fragment content - 35 to 70 percent
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Trude soils are on nearly level to gently sloping alluvial fans and outwash plains. Slopes range from 0 to 4 percent. Elevation ranges from 6,000 to 7,000 feet. The soil formed in coarse textured outwash and alluvium. The mean annual precipitation is 24 to 40 inches. The mean annual air temperature is 36 to 40 degrees F. The frost-free season is 30 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bootjack and Sawtelpeak series. Bootjack soils are fine-loamy over sandy or sandy-skeletal, poorly drained and are on lower terraces and floodplains. Sawtelpeak soils are coarse-loamy over sandy or sandy-skeletal and are on outwash plains.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately rapid permeability in the upper part and very rapid below.
USE AND VEGETATION: Trude soils are used principally as rangeland. The potential natural vegetation is mainly Idaho fescue, bluebunch wheatgrass, lupine, mountain big sagebrush and hotsprings big sagebrush.
DISTRIBUTION AND EXTENT: Trude soils are of small extent in southeastern Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Fremont County, Idaho, 1989.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to a depth of 5 inches (the A horizon)
Cambic horizon - the zone from 5 to 25 inches (the Bw1, Bw2, and Bw3 horizons)
Particle-size control section - the zone from 10 to 40 inches (part of Bw1, Bw2, Bw3 and part of the C horizon)