LOCATION CONPEAK WYEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, frigid, shallow Ustic Haplocalcids
TYPICAL PEDON: Conpeak gravelly fine sandy loam on northwest facing ridge top of 2 percent slope utilized as rangeland.
(Colors are for dry soil unless otherwise stated.)
A--0 to 2 inches; light brownish gray (10YR 6/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; strongly effervescent; carbonates disseminated and as thin coating on bottom of pebbles; 20 percent semiconsolidated sandstone pebbles; mildly alkaline (pH 7.6); abrupt smooth boundary. (1 to 4 inches thick)
Bk1--2 to 6 inches; pale brown (10YR 6/3) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure parting to weak fine granular; soft, very friable, nonsticky and nonplastic many very fine and fine roots; strongly effervescent, carbonates disseminated and as thin coating on bottom of pebbles; 20 percent semiconsolidated sandstone pebbles; moderately alkaline (pH 8.2); clear wavy boundary.
Bk2--6 to 14 inches; light brownish gray (2.5Y 6/2) fine sandy loam, grayish brown (2.5Y 5/2) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; strongly effervescent, carbonates disseminated and as many fine and medium soft masses, filaments, and thin coatings on bottom of pebbles; 40 percent semiconsolidated sandstone pebbles; moderately alkaline (pH 8.2); abrupt wavy boundary. (Combined thickness of Bk horizon is 8 to 19 inches.)
Cr--14 to 60 inches; soft, fine grained sandstone interbedded with thin lenses of siltstone.
TYPE LOCATION: Fremont County, Wyoming; 800 feet west, 1,400 feet north of the SE corner of sec. 1, T. 27 N., R. 100 W.
RANGE IN CHARACTERISTICS: Depth to bedrock is 8 to 20 inches. The mean annual soil temperature is 39 to 45 degrees F., and the mean annual summer soil temperature is 54 to 59 degrees F. Pebbles of semiconsolidated sandstone and siltstone range from 10 to 60 percent in the control section but break down upon pretreatment. Hard, consolidated coarse fragments range from 0 to 15 percent. The control section is loam or fine sandy loam with 5 to 18 percent clay, 10 to 45 percent silt, and 45 to 80 percent sand.
The A horizon has hue of 2.5Y or 10YR, value of 5 through 7 dry, 3 through 6 moist, and chroma of 2 or 3 dry and moist. Reaction is mildly through moderately alkaline.
The Bk calcic horizon has hue of 2.5Y or 10YR, value of 5 through 8 dry, 3 through 7 moist, and chroma of 2 or 3 dry and moist. Calcium carbonate equivalent ranges from 15 to 40 percent in the less than 20 mm. fraction. Reaction is moderately alkaline through strongly alkaline.
COMPETING SERIES: There are no competing series in the same family. Brownsto, Crago, and Luhon series are in the same subgroup and have bedrock deeper than 20 inches. Also, Crago soils are carbonatic and Luhon soils have summer soil temperatures warmer than 59 degrees F.
GEOGRAPHIC SETTING: The Conpeak soils are on hillslopes, ridges, and dissected pediments that have plane or convex surfaces. The slope gradient is commonly 5 to 20 percent but ranges from 2 to 45 percent. The soils formed in residuum and colluvial slopewash derived dominantly from sandstone and siltstone. Rock outcrops are common. Elevation is 7,000 to 8,500 feet. The mean annual temperature is 33 to 41 degrees F. The mean annual precipitation is 10 to 14 inches with the majority falling as snow in November through May 15, but these areas are windswept and only that precipitation falling in April and May enters the soil. Estimated frost-free season is 40 to 80 days.
DRAINAGE AND PERMEABILITY: Well drained; slow or medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used for grazing. Native vegetation is Indian ricegrass, needleandthread, Sandberg bluegrass, threadleaf sedge, and mat muhly.
DISTRIBUTION AND EXTENT: South central Wyoming. Series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Fremont County, Wyoming, Eastern part; 1985.