LOCATION YANKEEFORK IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Xeric Haplocryepts
TYPICAL PEDON: Yankeefork gravelly sandy loam--on a 4 percent east to northeast-facing slope in rangeland at 7,100 feet elevation. (Colors are for dry soil unless otherwise noted. When described on August 13, 1986, the soil was dry throughout.)
A--0 to 2 inches; brown (10YR 4/3) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and few medium roots; common very fine and fine irregular pores; 25 percent gravel; moderately acid (pH 6.0); clear smooth boundary. (2 to 5 inches thick)
AB--2 to 6 inches; yellowish brown (10YR 5/4) gravelly sandy loam, dark yellowish brown (10YR 3/4 ) moist; weak fine subangular blocky structure parting to weak fine granular; soft, very friable, nonsticky and nonplastic; many very fine and fine and few medium roots; common very fine and fine irregular pores; 25 percent gravel, dominantly fine; slightly acid (pH 6.2); clear smooth boundary. (4 to 10 inches thick)
Bw1--6 to 9 inches; yellowish brown (10YR 5/4) very gravelly sandy loam, dark yellowish brown (10YR 3/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and few medium roots; common very fine and fine irregular pores; 35 percent gravel, dominantly fine; slightly acid (pH 6.2); clear smooth boundary. (3 to 5 inches thick)
Bw2--9 to 17 inches; light yellowish brown (10YR 6/4) very gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; common very fine and fine irregular pores; 45 percent gravel, half are fine gravel; slightly acid (pH 6.4); clear wavy boundary. (7 to 12 inches thick)
BC--17 to 28 inches; light yellowish brown (10YR 6/4) very gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common very fine and fine roots; common fine, medium and coarse irregular pores; 40 percent gravel, 10 percent cobbles; slightly acid (pH 6.4); clear wavy boundary. (10 to 15 inches thick)
C1--28 to 46 inches; very pale brown (10YR 7/4) extremely gravelly coarse sand, yellowish brown ( 10YR 5/4) moist; single grain; loose; common medium and coarse irregular pores; 40 percent gravel , 20 percent cobbles, 1 percent stones; neutral (pH 6.8); gradual wavy boundary. (10 to 20 inches thick)
C2--46 to 60 inches; very pale brown (10YR 7/3) extremely gravelly coarse sand, yellowish brown (10YR 5/4) moist; single grain; loose; common medium and coarse irregular pores; 50 percent gravel, 20 percent cobbles, 10 percent stones; neutral (pH 6.8).
TYPE LOCATION: Blaine County, Idaho; about one half mile southwest of the Alturas Lake and Idaho Highway 93 junction, about 300 feet south and 1300 feet west of the northeast corner of section 16, T. 7 N., R. 14 E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 35 to 39 degrees F. Average summer soil temperature - 44 to 49 degrees F. Control section - Average percent clay: 5 to 12. Rock fragments - 50 to 90 percent.
A horizon
Value - 4 or 5 dry.
Chroma - 2 or 3 moist.
Reaction - strongly acid or moderately acid.
AB horizon
Texture - GR-SL, GRV-SL.
Coarse fragments - 25 to 50 percent.
Reaction - moderately acid or slightly acid.
Bw horizon
Value - 5 or 6 dry, 3 or 4 moist.
Texture - GR-SL, GRV-SL.
Coarse fragments - 30 to 55 percent.
Reaction - moderately acid or slightly acid.
BC horizon
Value - 5 or 6 dry, 3 or 4 moist.
Texture - GRV-SL, GRX-SL.
Rock fragments - 50 to 80 percent.
Reaction - moderately acid or slightly acid.
C horizon
Value - 5 or 6 moist.
Chroma - 3 or 4 dry or moist.
Texture - GRX-COS, CBX-COS.
Rock fragments - 60 to 90 percent, with 1 to 10 percent stones.
Reaction - neutral or slightly acid.
COMPETING SERIES: These are the Ketchum, Longhike (T), Muiral, and Snacreek (T) series. The Ketchum soils have O horizons, mean summer soil temperatures of 54 to 59 degrees F., and have a neutral reaction in the solum. Longhike and Muiral soils are moderately deep. Snacreek soils do not have a cambic horizon, have an O horizon, have a mollic epipedon and are moderately well drained with a water table below 1 meter-.
GEOGRAPHIC SETTING: Yankeefork soils are on outwash fans, fan terraces and stream terraces. These soils formed in glacial outwash and alluvium. Slopes are 2 to 6 percent and elevations are 6,300 to 7 ,500 feet. The climate is cold and moist in winter and spring and cool in summer. Average annual precipitation is 16 to 19 inches. Average annual temperature is 34 to 38 degrees F. The frost-free period is 5 to 30 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Busterback, Castlepeak, Langer, and Struggle soils. Busterback soils are on stream terraces and outwash fans, are pachic and have loamy-skeletal particle-size control sections. Castlepeak soils are on outwash fans, fan terraces, and stream terraces. Castlepeak soils have sandy-skeletal particle-size control sections and lack a cambic horizon. Langer soils are on hills and mountains and have mollic epipedons. Struggle soils are on moraines and have sandy-skeletal particle-size control sections.
DRAINAGE AND PERMEABILITY: Well drained. Slow runoff. Moderately rapid permeability in the upper part and very rapid in the lower part of the profile.
USE AND VEGETATION: Rangeland and irrigated pasture. The natural vegetation is mountain big sagebrush and Idaho fescue.
DISTRIBUTION AND EXTENT: Central Idaho. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Custer-Lemhi Counties, Idaho, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 6 inches (A and AB horizons).
Cambic horizon - The zone from 6 to 17 inches (the Bw1 and Bw2 horizons).
Particle-size control section - The zone from 10 to 40 inches (part of the Bw2, the BC, and part of the C1 horizons).
The 3/2008 description reflects a change in classification from Loamy-skeletal, mixed, superactive Xeric Eutrocryepts to Loamy-skeletal, mixed, superactive Xeric Haplocryepts due to revision of the cryepts great groups and subgroups. The competing series section was not updated and should be reviewed after all the cryepts have been re-classified.