LOCATION MULSTAY COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Aridic Haplustalfs
TYPICAL PEDON: Mulstay stony loam - grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 4 inches; grayish brown (10YR 5/2) stony loam, dark grayish brown (10YR 4/2) moist; weak subangular blocky structure that parts to moderate fine granular; soft, friable, slightly sticky and slightly plastic; 5 percent large basalt stones; neutral; clear wavy boundary. (2 to 6 inches thick)
B21t--4 to 11 inches; pale brown (10YR 6/3) heavy clay loam, brown (10YR 5/3) moist; strong coarse subangular blocky structure that parts to strong medium subangular blocky; hard, firm, very sticky and very plastic; thin continuous clay films on faces of peds; 2 to 5 percent angular basalt cobbles; neutral; gradual wavy boundary. (8 to 12 inches thick)
B22t--11 to 21 inches; pale brown (10YR 6/3) heavy clay loam, brown (10YR 5/3) moist; strong coarse angular blocky structure that parts to strong medium subangular blocky; very hard, very firm, very sticky and very plastic; thin continuous clay films on faces of peds; 2 to 5 percent angular basalt stones; neutral; gradual wavy boundary. (8 to 12 inches thick)
IIB23t--21 to 55 inches; light yellowish brown (2.5Y 6/4) clay loam, light olive brown (2.5Y 5/4) moist; strong coarse angular blocky structure that parts to moderate medium angular blocky; very hard, firm, very sticky and very plastic; thin nearly continuous clay films on faces of peds; few fine shale chips; mildly alkaline; gradual smooth boundary. (12 to 36 inches thick)
IIB3--55 to 60 inches; light yellowish brown (2.5Y 6/4) clay loam, light olive brown (2.5Y 5/4) moist; common medium prominent brownish yellow (10YR 6/6) mottles; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; thin patchy clay films on faces of peds; few fine shale chips; mildly alkaline; gradual smooth boundary. (4 to 8 inches thick)
IIC--60 to 72 inches; light yellowish brown (2.5Y 6/4) clay loam, light olive brown (2.5Y 5/6) moist; many medium prominent brownish yellowish (10YR 6/6) mottles; massive; hard, firm, slightly sticky and slightly plastic; many fine shale chips; mildly alkaline.
TYPE LOCATION: Grand County, Colorado; about 18 miles north of Kremmling and 1.5 miles northeast of Highway 40 on Chimney Rock Road; approximately 1,000 feet south and 700 feet east of NW corner of Sec. 35, T. 4 N., R. 81 W.
RANGE IN CHARACTERISTICS: The solum ranges from 40 to 80 inches thick. Rock fragments on the surface range from 0 to 15 percent and are mainly 10 to 24 inches in diameter. Rock fragments in the upper two feet are dominantly basalt cobbles and stones and range from 0 to 10 percent by volume. Rock fragments in the lower part of the profile are mainly fine shale chips which increase in quantity with increasing depth. The mean annual soil temperature is about 38 to 40 degrees F.
The A horizon has hue of 10YR through 5Y, value of 4 or 5 moist, 4 through 6 dry, and chroma of 2 or 3. This horizon is commonly loam but ranges to light clay loam.
The B horizon has hue of 10YR through 5Y, value of 4 through 6 moist; 5 through 7 dry, and chroma of 2 through 5. This horizon is heavy clay loam or clay and averages more than 35 percent clay. The lower part ranges from clay loam to heavy clay loam.
The C horizon has hue of 10YR through 5Y and ranges from clay loam to clay.
COMPETING SERIES: These are the Boettcher, Creswell, Kather and Pinelli series. Boettcher and Kather soils have a paralithic contact at depths of less than 40 inches. Creswell soils have a lithic contact at depths of less than 40 inches. Pinelli soils have horizons of visible secondary calcium carbonate accumulation.
GEOGRAPHIC SETTING: Mulstay soils are on mountain side slopes and have slopes of 6 to 50 percent. Elevations range from 7,800 to 8,800 feet. The soils formed in material weathered from basalt over material weathered from shale. Mean annual precipitation ranges from 14 to 18 inches. Mean annual temperature is about 36 degrees F., mean summer temperature is about 56 degrees F., and the frost-free season is about 40 to 50 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Clayburn, Harsha, Mord and Quander soils. Clayburn soils are pachic and fine-loamy. Harsha soils are fine-loamy and have ca horizons. Mord soils have dark colored surface layers and albic horizons. Quander soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; moderate runoff; slow permeability.
USE AND VEGETATION: These soils are used for grazing and wildlife. Native vegetation is mainly wheatgrasses, junegrass, big sagebrush, rabbitbrush, and lupine.
DISTRIBUTION AND EXTENT: North-central Colorado. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Grand County, Colorado, 1977.
REMARKS: Last updated by the state 3/77.