LOCATION ULA                     CO

Established Series
Rev. DLA/GB/KLS
11/2022

ULA SERIES

The Ula series consists of moderately deep, well drained soils that formed in material weathered from sandstone. Ula soils are on mountain foot slopes and side slopes and have slopes of 2 to over 60 percent. The mean annual precipitation is about 640 mm and mean annual air temperature is about 4 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive Ustollic Haplocryalfs

TYPICAL PEDON: Ula cobbly sandy loam - forested. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 3 cm; undecomposed oak leaves and pine needles.

A--3 to 16 cm; 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. (10 to 20 cm thick)

E--16 to 34 cm; 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. (8 to 25 cm thick)

Bt1--34 to 47 cm; 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.

Bt2--47 to 88 cm; 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. (Combined thickness of Bt horizons - 30 to 70 cm)

BC--88 to 98 cm; 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. (5 to 15 cm thick)

Cr--98 to 123 cm; weathered conglomerate sandstone.

TYPE LOCATION: Custer County, Colorado; about 8 km west and 1.5 km south of the town of Westcliffe, Colorado; about 215 meters west and 140 meters south of the northeast corner of sec. 32, T. 22 S., R. 73 W.; USGS Horn Peak quadrangle; lat. 38 degrees, 6 minutes, 9 seconds N. and long. 105 degrees, 33 minutes, 42 seconds W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--4 to 8 degrees C
Mean summer soil temperature--7 to 8 degrees C
Depth to paralithic contact--50 to 100 cm
Base saturation--60 to 100 percent
Rock fragment content--15 to 35 percent and are mostly angular cobbles and pebbles
The soil is noncalcareous throughout.

A horizon
Hue--5YR or 7.5YR
Value--4 or 5 dry, 2 or 3 moist
Chroma--1 through 3
Reaction--pH 6.1 to 7.8

E horizon
Hue--2.5YR or 5YR
Value--6 through 8 dry, 4 through 7 moist
Chroma--2 through 6
Reaction--pH 6.1 to 7.3

Bt horizon
Hue--10R through 5YR
Value--5 through 7 dry, 4 through 6 moist
Chroma--2 through 6
Texture--sandy clay loam
Clay content--18 to 35 percent in the fine earth fraction
Silt content--5 to 35 percent
Sand content--40 to 75 percent, with more than 35 percent being fine or coarser sand
Rock fragment content--15 to 35 percent angular gravel and cobbles
Reaction--pH 6.1 to 7.3

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 100 cm. Amerant has mean summer soil temperature of more than 8 degrees C. Beardal and Swapps soils have a lithic contact above a depth of 100 cm. Rimton soils have a mixed E/B horizon and have hue yellower than 5YR in all horizons. Wix soils have hues of 10YR and yellower in the Bt horizon.

GEOGRAPHIC SETTING:
Landform--mountain foot slopes and side slopes
Elevation--2375 to 3050 meters
Slope--2 to over 60 percent
Parent material--residuum weathered or reworked from sandstone
Mean annual precipitation--460 to 710 mm
Mean annual air temperature--3 to 6 degrees C

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

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 Gambel oak.

DISTRIBUTION AND EXTENT: Ula soils are of small extent in the mountains of southcentral Colorado; MLRA 48A.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Custer County Area, Colorado, 1979

REMARKS: Diagnostic horizons and features in this pedon include:
Mollic epipedon (Ustollic feature)--3 to 16 cm (A horizon)
Argillic horizon--34 to 88 cm (Bt1 and Bt2 horizons)
Paralithic contact--98 cm to weathered conglomerate sandstone (Cr horizon)
Particle-size control section--34 to 88 cm (Bt1 and Bt2 horizons)

Converted to metric, updated formatting, and O horizons were updated to start at zero. Competing series section was not updated. 11/2022

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National Cooperative Soil Survey
U.S.A.