LOCATION ULA COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Ustollic Haplocryalfs
TYPICAL PEDON: Ula cobbly sandy loam - forested. (Colors are for dry soil unless otherwise noted.)
0i--1 inch to 0; undecomposed oak leaves and pine needles.
A--0 to 5 inches; reddish gray (5YR 5/2) cobbly sandy loam, dark reddish brown (5YR 3/2) moist; moderate fine granular structure; slightly hard, very friable; 10 percent cobbles, 10 percent pebbles; common medium and coarse roots; neutral; clear wavy boundary. (4 to 8 inches thick)
E--5 to 12 inches; light reddish brown (5YR 6/4) cobbly sand loam, reddish brown (5YR 5/4) moist; weak medium subangular blocky structure parting to weak fine granular; slightly hard, very friable; 5 percent stones, 10 percent cobbles, 10 percent pebbles; common medium and coarse roots; neutral; gradual wavy boundary. (3 to 10 inches thick)
Bt1--12 to 17 inches; light reddish brown (5YR 6/4) cobbly sandy loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky; 5 percent stones, 10 percent cobbles, 10 percent pebbles; common medium and coarse roots; few faint clay films in fine tubular or interstitial pores; neutral; gradual wavy boundary. (3 to 8 inches thick)
Bt2--17 to 33 inches; reddish brown (5YR 5/4) cobbly sandy clay loam, reddish brown (5YR 4/4) moist weak coarse prismatic structure parting to moderate medium blocks; very hard, friable, sticky and plastic; 5 percent stones; 10 percent cobbles, 10 percent percent pebbles; common medium and coarse roots; many distinct clay films on faces of peds; slightly acid; gradual wavy boundary. (9 to 20 inches thick)
BC--33 to 37 inches; yellowish red (5YR 5/6) cobbly sandy clay loam, yellowish red (5YR 4/6) moist, reddish brown (5YR 4/4) crushed moist; moderate medium subangular blocky structure; very hard, friable, slightly sticky; 5 percent stones, 10 percent cobbles, 10 percent pebbles, few coarse roots; few faint clay films on faces of peds; slightly acid; gradual wavy boundary. (2 to 6 inches thick)
Cr--37 to 47 inches; weathered conglomerate sandstone.
TYPE LOCATION: Custer County, Colorado; about 5 miles west and 1 mile south of the town of Westcliffe, Colorado; 700 feet west and 450 feet south of the northeast corner of Sec. 32, T. 22 S., R. 73 W. U.S.G.S. Horn Peak quadrangle; lat. 38 degrees, 6 minutes, 9 seconds N. and long. 105 degrees, 33 minutes, 42 seconds W.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact ranges from 20 to 40 inches. The soil is noncalcareous throughout. Base saturation ranges from 60 to 100 percent. Rock fragments range from 15 to 35 percent and are mostly angular cobbles and pebbles. Mean annual soil temperature ranges from 40 to 46 degrees F., and mean summer soil temperature ranges from 44 to 47 degrees F.
The A horizon has hue of 5YR or 7.5YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 1 through 3. It ranges from slightly acid to mildly alkaline.
The E horizon has hue of 2.5YR or 5YR, value of 6 through 8 dry, 4 through 7 moist, and chroma of 2 through 6. It is slightly acid or neutral.
The Bt horizon has hue of 10R through 5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 through 6. It is typically cobbly or gravelly sandy clay loam, but the fine earth fraction has 18 to 35 percent clay, 5 to 35 percent silt, 40 to 75 percent sand, with more than 35 percent being fine or coarser sand. This horizon is slightly acid or neutral.
COMPETING SERIES: These are the Amerant (WY), Beardal (UT), Bramard (ID), Dunlatop (CO), Hub (WY), Nisula (ID), Rimton (WY), Stringam (ID), Swapps (UT), Telcher (ID), and Wix (CO) series.
Bramard, Dunlatop, Hub, Nisula, Stringam, and Telcher soils lack a paralithic contact above a depth of 40 inches. Amerant has mean summer soil temperature of more than 47 degrees F. Beardal and Swapps soils have a lithic contact above a depth of 40 inches. Rimton soils have a mixed E/B horizon and have hue yellower than 5YR in all horizons. Wex soils have hues of 10YR and yellower in the Bt horizon.
GEOGRAPHIC SETTING: Ula soils are on mountain foot slopes and side slopes. Slopes range from 2 to over 60 percent. The soils formed in material weathered or reworked from sandstone. Elevations range from 7,800 to 10,000 feet. Average annual precipitation ranges from 18 to 28 inches and the average annual temperature ranges from 38 to 42 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Leadville and Curecanti soils both of which have more than 35 percent rock fragments in the major part of the solum.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: Used mainly for timber production, wildlife habitat, and limited grazing. Vegetation is mainly ponderosa pine, white fir and aspen with an understory of kinnikinnick, mountain muhly, junegrass, mountain brome, and oak brush.
DISTRIBUTION AND EXTENT: South-central Colorado. Series is of small extent.
MLRA OFFICE RESPONSIBLE: Lakewood, Colorado
SERIES ESTABLISHED: Custer County Area, Colorado, 1979.
REMARKS: Diagnostic features include a typical mollic epipedon from 0 to 5 inches and an argillic horizon from 12 to 33 inches. Last updated by the state 4/94.