LOCATION RHYLOW IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic Vitrandic Humicryepts
TYPICAL PEDON: Rhylow gravelly ashy loam, supporting a subalpine fir/grouse blueberry plant association, pinegrass phase, woodland; on an east slope of 25 percent; about 6,880 feet elevation. (Colors are for air dry soil unless otherwise noted.)
Oi--0 to 0.5 inches; forest litter of needles and leaves; abrupt broken boundary.
A1--0.5 to 4 inches; brown (10YR 4/3) gravelly ashy loam, very dark grayish brown (10YR 3/2) moist; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, common fine, and few medium and coarse roots; many very fine irregular pores; 15 percent gravel; moderately acid (pH 5.8); clear smooth boundary. (4 to 8 inches thick)
A2--4 to 14 inches; brown (10YR 5/3) gravelly ashy loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure parting to weak fine granular; soft, very friable, nonsticky and nonplastic; many very fine, common fine, and few medium and coarse roots; many very fine irregular pores; 20 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (4 to 12 inches thick)
Bw--14 to 32 inches; yellowish brown (10YR 5/4) gravelly ashy loam, dark yellowish brown (10YR 3/4) moist; moderate coarse subangular blocky structure parting to moderate fine subangular blocky; soft, very friable, nonsticky and slightly plastic; common very fine and few fine, medium and coarse roots; many very fine tubular pores; 30 percent gravel; moderately acid (pH 6.0); gradual wavy boundary. (10 to 30 inches thick)
BC--32 to 50 inches; light yellowish brown (10YR 6/4) extremely cobbly ashy sandy loam, yellowish brown (10YR 5/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and few fine, medium and coarse roots; many very fine tubular pores; 20 percent gravel, 40 percent cobbles, and 10 percent stones and boulders; moderately acid (pH 5.9); diffuse wavy boundary. (10 to 30 inches thick)
C--50 to 65 inches; pale brown (10YR 6/3) extremely cobbly sandy loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; many very fine tubular pores; 15 percent gravel, 45 percent cobbles, 25 percent stones and boulders; moderately acid (pH 5.9).
TYPE LOCATION: Fremont County, Idaho; about 17 miles northeast of Ashton, Idaho; about 2,200 feet west and 2,400 feet south of the northeast corner of section 5, T. 10 N., R. 45 E.; Latitude - 44 degrees, 13 minutes, 27 seconds North; Longitude - 111 degrees, 9 minutes, 40 seconds West.
RANGE IN CHARACTERISTICS:
Umbric epipedon thickness - 10 to 20 inches
Depth of solum - 40 to greater than 60 inches
Clay in the particle-size control section - 5 to 18 percent
Rock fragments in the particle-size control section, weighted average - 35 to 60 percent
Volcanic glass content - 5 to 30 percent in the 0.02 to 2.0 mm fraction
Ammonium acetate extractable Al plus Fe - 0.1 to 1.0 percent
Phosphate retention - 20 to 50 percent
Reaction - moderately acid to slightly acid
Mean annual soil temperature - 36 to 41 degrees F.
Mean summer soil temperature - 42 to 47 degrees F. with an O horizon, 48 to 52 degrees F. without an O horizon
Moisture control section - between 8 and 24 inches; dry in all parts of the moisture control section for 15 to 45 consecutive days during the four months following the summer solstice
O horizon
Thickness - 1/2 to 2 inches thick
Form - Commonly forest liter of leaves, needles and stems on lightly or undisturbed pedons. On pedons where recent, heavy mechanical disturbance has occurred a root mat of pinegrass, elk sedge or both is common.
A horizons
Hue - 10YR or 7.5YR
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Clay content - 7 to 15 percent
Rock fragment content - 15 to 60 percent
Gravel - 15 to 55 percent
Cobbles - 0 to 5 percent
Stones - 0 to 5 percent
Base saturation by ammonium acetate - 25 to 50 percent
Bw horizon
Hue - 7.5YR, 10YR or 2.5Y
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Texture, less than 2 mm - ashy loam or ashy sandy loam
Clay content - 5 to 18 percent
Rock fragments - 20 to 60 percent
Gravel - 20 to 50 percent
Cobbles - 0 to 10 percent
Stones - 0 to 5 percent
Acid oxalate extractable Al plus 1/2 Fe - 0.1 to 0.6 percent
Base saturation by ammonium acetate - 25 to 50 percent
BC horizon
Hue - 10YR or 2.5Y
Value - 5 to 7 dry, 4 to 6 moist
Chroma - 2 to 4 dry or moist
Texture, less than 2 mm - sandy loam, loam, ashy sandy loam or ashy loam
Clay content - 5 to 12 percent
Rock fragments - 40 to 80 percent
Gravel - 10 to 30 percent
Cobbles - 30 to 60 percent
Stones - 0 to 15 percent
Base saturation by ammonium acetate - 30 to 80 percent
C horizon
Hue - 10YR or 2.5Y
Value - 6 to 7 dry, 5 or 6 moist
Chroma - 2 to 4 dry or moist
Clay content - 4 to 8 percent
Rock fragments - 80 to 90 percent
Gravel - 5 to 30 percent
Cobbles - 40 to 60 percent
Stones - 20 to 55 percent
Base saturation by ammonium acetate - 30 to 80 percent
COMPETING SERIES: These are the Potrmound and Prong series. Potrmound and Prong soils are 20 to 40 inches deep to a lithic contact.
GEOGRAPHIC SETTING: The Rhylow soils are on disected tablelands, incised drainageways and sideslopes of foothills and mountains. Slopes are complex and range from 4 to 70 percent. The soil formed in colluvium or local alluvium from loess, volcanic ash and igneous and sedimentary rocks. Cobbles and stones are dominantly angular. Elevations range from 5,300 to 10,000 feet. The mean annual precipitation is 22 to 35 inches. The mean annual air temperature is 29 to 39 degrees F. The frost-free season is less than 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fitzwil and Koffgo series. These soils occur intermixed with the Rhylow soils. Fitzwil soils have thick E horizons to depths of 24 to 40 inches over an argillic horizon. Koffgo soils have ochric epipedons.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Rhylow soils are used for wildlife habitat, recreation and woodland. These soils commonly support lodgepole pine/grouse whortleberry, lodgepole pine/pinegrass and Douglas fir/pinegrass communities. Recent clearcut areas of these soils support communities dominated by pinegrass or elk sedge. The potential native vegetation are the subalpine fir/grouse whortleberry and subalpine fir/pinegrass plant associations.
DISTRIBUTION AND EXTENT: Southeastern Idaho and northwestern Wyoming. The soil is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Targhee National Forest, Fremont County, Idaho, 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - the zone from the mineral soil surface to 14 inches (the A1 and A2 horizons)
Cambic horizon - the zone from 14 to 50 inches (the Bw and BC horizons)
Particle-size control section - the zone from 10 to 40 inches (part of the A2, the Bw, and part of the BC horizons)
Vitrandic subgroup feature - the zone from the mineral soil surface to 50 inches (A1, A2, Bw and BC horizons)
Moisture regime - udic
ADDITIONAL DATA: Full characterization data (8/96) NSSL Lincoln, NE. Client assigned lab number: S94ID-043-002
Project file number 95P-27; lab assigned number: Pedon 95P 149. Samples: 95P 1025-1029
The 3/2008 description reflects a change in classification from Loamy-skeletal, isotic Vitrandic Dystrocryepts to Loamy-skeletal, isotic Vitrandic Humicryepts 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.