LOCATION RYORP MTEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Ustic Haplocryepts
TYPICAL PEDON: Ryorp sandy loam - lodgepole pine forest. (Colors are for dry soil unless otherwise noted.)
0e--0 to 2 inches; loose mat of partly decomposed pine needles and twigs.
E--2 to 4 inches; light brownish gray (10YR 6/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak thin platy structure; soft, very friable, nonsticky, nonplastic; many coarse and medium, and common fine and very fine roots; slightly acid (pH 6.2); clear smooth boundary. (1 to 3 inches thick)
Bw--4 to 23 inches; pale brown (10YR 6/3) fine sandy loam grading to sandy loam, brown (10YR 4/3) moist; few coarse yellowish brown (10YR 5/4) iron mottles with diffuse boundaries; moderate grading to weak coarse prismatic structure; slightly hard, very friable, nonsticky, nonplastic; common coarse, medium, fine and very fine roots and pores in upper part grading to common fine, and very fine roots and pores in the lower part; slightly acid (pH 6.1); gradual wavy boundary. (14 to 30 inches thick)
C--23 to 36 inches; pale brown (10YR 6/3) sandy loam, brown (10YR 5/3) moist; massive; hard, very friable, nonsticky, nonplastic; few fine roots and tubular pores; moderately acid (pH 6.0); abrupt boundary. (7 to 16 inches thick)
R--36 inches; noncalcareous sandstone.
TYPE LOCATION: Big Horn County, Montana; 1/4 mile below fire lookout tower, 95 feet south of trail, 650 feet east of trail fork, T63, R26E.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 39 to 45 degrees F. and average summer soil temperature ranges from 44 to 46 degrees F. under a close forest canopy and an 0 horizon. The Bw and upper C horizons have about 12 to 18 percent clay. The soil has hue of 2.5Y through 7.5YR. It is slightly to medium acid. Depth to sandstone bedrock is 20 to 40 inches. Sandstone and cherty sandstone fragments range from 1 to 30 percent of the soil volume above sandstone rock.
COMPETING SERIES: These are the Bobowic, Kismuth, and Upson series. All of these soils have a paralithic contact within 40 inches of the mineral soil surface.
GEOGRAPHIC SETTING: The Ryorp soils occur at high elevations (6,000 to 9,000 feet) on sandstone bedrock plateaus and mountains in a cold subhumid climate with a frost-free season ranging from 50 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hanson, Latang, Little Horn, Sicklesteets and Snowy soils. Hanson, Latang, Little Horn and Snowy soils formed from limestone materials. Sicklesteets soils have argillic horizons and formed under forest cover.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; rapid permeability.
USE AND VEGETATION: Native range. The cover is mainly lodgepole pine.
DISTRIBUTION AND EXTENT: South-central Montana. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Big Horn County (Big Horn Area), Montana, 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to 4 inches (Oi and E horizon);
Albic horizon - the zone from 2 to 4 inches (E horizon);
Cambic horizon - the zone from 4 to 23 inches (Bw horizon);
Particle-size control section - the zone from 10 to 40 inches;
Ustic moisture regime.
The 3/2008 description reflects a change in classification from Coarse-loamy, mixed, superactive Ustic Eutrocryepts to Coarse-loamy, mixed, superactive Ustic 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.