LOCATION COMER WY+MTTentative Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, nonacid, frigid Ustic Torriorthents
TYPICAL PEDON: Comer fine sandy loam - grassland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 6 inches; light brownish gray (10YR 6/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; soft, very friable; noncalcareous, slightly alkaline, pH 7.7 (PR); gradual wavy boundary. (4 to 8 inches thick).
C--6 to 60 inches; brown (10YR 5/3) fine sandy loam, brown (10YR 4/3) moist; massive; slightly hard, very friable; 2 percent sandstone fragments; noncalcareous, slightly alkaline, pH 7.7 (PR).
TYPE LOCATION: Lincoln County, Wyoming. 1,320 feet east and 200 feet north of the SW corner of sec. 24, T 21N, R 116W.
RANGE IN CHARACTERISTICS: These soils have ochric epipedons. Typically they are noncalcareous for 60 inches, but must be noncalcareous for more than 40 inches. There should be no bedrock or strongly contrasting substratums above 40 inches. Organic carbon content normally ranges from .4 to 1.5 percent in the A horizon and decreases uniformly with depth. Conductivity is usually less than 2 millimho but should not exceed 16 millimhos. Exchangeable sodium percentage is usually less than 1 percent but should not exceed 15 percent. The soil is bast saturated. Content of coarse fragments ranges from 0 to 15 percent but is generally less than 5 percent. Texture of the control section is typically a fine sandy loam but clay may range from 5 to 18 percent, silt from 5 to 40 percent, and sand from 50 to 80 percent with more than 35 percent being fine or coarser sand. Any loamy sand coarser than loamy very fine sand is exempt from the above range. The mean annual soil temperature ranges from 32 degrees F. to 46 degrees F., and the mean summer soil temperature ranges from 59 degrees F. to 70 degrees F. In 7 out of 10 years these soils are moist in some part of the moisture control section for more than 1/4 but less than 1/2 the time the soil temperature at 20 inches is above 41 degrees F., and they are moist in all parts of the moisture control section for less than 60 cumulative days during the 120 days following the winter solstice.
Color of the A horizon may range in hue from 5Y to 7.5YR, in value from 5 to 6 dry or 3 to 5 moist, and in chroma from 2 to 3. When the value of the A horizon is as dark as 5 dry and 3 moist the horizon must be too thin, or contain too little organic matter to be a mollic epipedon. Reaction normally ranges from pH 6.6 to pH 7.8 (1:5 dilution organic dye). Primary structure is usually granular but may be subangular blocky. Consistence ranges from soft to slightly hard.
Hue of the C horizon ranges from 5Y to 7.5YR. Reaction normally ranges from pH 6.6 to pH 7.8 (1:5 dilution organic dye). Texture is usually a fine sandy loam.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The Comer series occurs on gently to moderately sloping alluvial fans. Slopers typically range from 1 percent to about 15 or more percent. The soils is developing in thick, noncalcareous, moderately coarse textured materials derived from sedimentary rocks. At the type location the average annual precipitation is 10 inches with peak periods of precipitation occurring in the spring and early summer months. Mean annual air temperature is 60 degrees F.., mean annual soil temperature is 45 degrees F., and mean summer soil temperature is 61 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Blazon and Quealy series. The Blazon series differs in having finer textures and in having a lithic contact above 20 inches. The Quealy series differs in having a cambic horizon, in being finer textured and in overlying a lithic contact between 10 and 20 inches.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow. Permeability is rapid.
USE AND VEGETATION: These soils are used principally as native pastureland, but may be irrigated in places. Native vegetation includes sage, snakeweed, and cheatgrass.
DISTRIBUTION AND EXTENT: Present known distribution limited to the high mountain valleys of Wyoming and Colorado. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Lincoln County, Wyoming, 1970.