LOCATION HOWLETT COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Ustic Haplocryalfs
TYPICAL PEDON: Howlett cobbly sandy loam, on a north facing, convex, 22 percent slope in mixed conifers at an elevation of 9,350 feet. (Colors are for dry soil unless otherwise noted.) When described on July 15, 1983 the soil was moist from 0 to 65 inches. The surface is covered by 1 percent stones.
Oi--0 to 2 inches; slightly decomposed plant material.
E--2 to 14 inches; pinkish gray (5YR 6/2) cobbly sandy loam, reddish brown (5YR 4/3) moist; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; common fine, medium and coarse roots; 10 percent gravel, 10 percent cobbles, 1 percent stones; slightly acid (pH 6.4); clear smooth boundary. (9 to 20 inches thick)
Bt1--14 to 23 inches; weak red (2.5YR 5/2) gravelly sandy clay loam, weak red (2.5YR 4/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine to coarse roots; common continuous clay films on faces of peds; 15 percent gravel, 5 percent cobbles; slightly acid (pH 6.1); clear smooth boundary.
Bt2--23 to 47 inches; reddish brown (2.5YR 5/3) gravelly sandy clay loam, reddish brown (2.5YR 4/4) moist; strong medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few fine and medium roots; many continuous clay films on faces of peds; 20 percent gravel, 5 percent cobbles; slightly acid pH 6.4); clear wavy boundary. (Combined thickness of the Bt1 and Bt2 horizons is 28 to 40 inches thick)
BCt--47 to 65 inches; reddish brown (2.5YR 4/4) very cobbly sandy clay loam, dark reddish brown (2.5YR 3/4) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine and medium roots; few continuous clay films on faces of peds; 15 percent gravel, 30 percent cobbles; neutral pH 6.6).
TYPE LOCATION: Las Animas County, Colorado; about 3 miles northwest of Stonewall; located in an unsectionalized area west of Hwy. 12 on the Hell Canyon trail, T. 33 S., R. 69 W.; Stonewall USGS quad; lat. 37 degrees 10 minutes 23 seconds N. and long. 105 degrees 4 minutes 58 seconds W., NAD 1927
RANGE IN CHARACTERISTICS: (depths listed are from the mineral soil surface)
Soil moisture: The soil moisture control section is moist continuously March through September, driest December though February; Udic moisture regime bordering on ustic.
Mean annual soil temperature: 36 to 40 degrees F
Mean summer soil temperature: 44 to 48 degrees F
Depth to albic horizon: 0 to 2 inches
Depth to base of the argillic horizon: 65 inches or more
Thickness of the albic horizon: 8 to 20 inches
Other features: a thin A horizon is present in some pedons
Particle-size control section (weighted average):
Clay content: 18 to 35 percent
Sand content: 40 to 65 percent
Rock fragments: 15 to 35 percent
E horizon:
Hue: 5YR or 7.5YR
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 2 or 3
Clay content: 10 to 20 percent
Rock fragments: 5 to 35 percent
Reaction: moderately acid to neutral
Bt horizons:
Hue: 2.5YR or 5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6
Texture of the fine earth fraction: sandy clay loam, clay loam
Clay content: 20 to 35 percent
Rock fragments: 15 to 35 percent
Base saturation: 60 to 100 percent
Reaction: slightly acid or neutral
BCt horizon:
Hue: 2.5YR or 5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 3 to 6
Clay content: 20 to 35 percent
Rock fragments: 35 to 60 percent
Base saturation: 60 to 100 percent
Reaction: slightly acid or neutral
COMPETING SERIES: These are the
Ansel (WY),
Edloe (CO), Weminuchue (CO), and
Wix (CO) series.
Ansel soils: have hues of 7.5YR or yellower
Edloe soils: have a lithic contact at depths of 20 to 40 inches
Weminuchue soils: have an E/B horizon.
Wix soils: have a paralithic contact at depths of 20 to 40 inches
GEOGRAPHIC SETTING:
Parent material: slope alluvium and colluvium derived from sandstone, commonly the Sangre De Cristo Formation.
Landform: mountain slopes
Slopes: 5 to 40 percent
Elevation: 8,500 to 10,800 feet
Mean annual temperature: 37 to 42 degrees F
Mean annual precipitation: 20 to 26 inches
Precipitation pattern: continental
Wettest period: April through August
Driest period: December through February
Frost-free period: 40 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Leadville and Scandard series. The Leadville soils average more than 35 percent rock fragments and are on mountain slopes. The Scandard soils have a lithic contact at depths of 20 to 40 inches and are on mountain slopes.
DRAINAGE AND PERMEABILITY: Well drained, rapid runoff, moderate permeability.
USE AND VEGETATION: Woodland and wildlife habitat; the native vegetation is mainly Rocky Mountain Douglas fir and white fir with lesser amounts of quaking aspen, Engelmann's spruce and subalpine fir. The understory consists of common juniper, kinninnick, woods rose, Oregon grape, elk sedge, Arizona fescue and mountain muhly.
DISTRIBUTION AND EXTENT: Southern Rocky Mountains, Colorado; LRR E, MLRA 48A; small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Las Animas County, Colorado, Las Animas Area soil survey, Colorado, 2007. The name was taken from a creek.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 14 to 65 inches.
Particle-size control section: The zone from 14 to 34 inches. (Bt1 and part of the Bt2 horizons)
Albic horizon: The zone from 2 to 14 inches. (E horizons)
Argillic horizon: The zone from 14 to 65 inches. (Bt1, Bt2, BCt horizons)
Other features: Udic moisture regime bordering on ustic.
The assignment of the cation-exchange activity class is supported by lab sample numbers S99-CO071-004.
Taxonomic Version: Eighth Edition, 1998
ADDITIONAL DATA: Lab sample S99-CO071-004