LOCATION HAPJACK WYEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Lithic Haplocryalfs
TYPICAL PEDON: Hapjack gravelly sandy loam on a northwest-facing convex slope of about 5 percent in native grasses and sagebrush. There is 70 percent pebble lag on surface. (Colors are for dry soil unless otherwise stated.)
A--0 to 3 inches; brown (7.5YR 5/2) gravelly sandy loam, dark brown (7.5YR 3/2) moist; moderate medium and fine granular structure; soft, very friable, slightly sticky and nonplastic; common very fine and fine and few medium roots; 20 percent pebbles; neutral (pH 7.0); abrupt smooth boundary. (2 to 4 inches thick)
Bt--3 to 10 inches; brown (7.5YR 5/4) gravelly sandy clay loam, dark brown (7.5YR 4/4) moist; strong coarse and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine, fine, and medium roots; continuous thin clay films on faces of peds; 33 percent pebbles; neutral (pH 7.0); clear smooth boundary. (4 to 8 inches thick)
C--10 to 19 inches; brown (7.5YR 5/4) extremely gravelly sandy loam, brown (7.5YR 4/4) moist; massive, soft, very friable, nonsticky and nonplastic; very few very fine and fine roots; 62 percent pebbles; neutral (pH 7.2); abrupt irregular boundary. (0 to 9 inches thick)
R--19 inches; hard Sherman granite.
TYPE LOCATION: Albany County, Wyoming; about 15 miles southeast of Laramie; approximately 1,800 feet east and 40 feet north of the SW corner of sec. 24, T. 14 N., R. 72 W.
RANGE IN CHARACTERISTICS: Depth to bedrock is 10 to 20 inches. Depth to the base of the Bt (argillic) horizon is 10 inches or less. The mean annual soil temperature ranges from 35 to 45 degrees F., and the mean summer soil temperature ranges from 50 to 59 degrees. The particle size control section includes the Bt horizon and underlying C horizons. Clay content of the particle size control section ranges from 15 to 24 percent. Rock fragment content of the particle size control section ranges from 35 to 60 percent and is mostly fine gravel with some coarse gravel. The surface typically is covered by a lag of 25 to 80 percent fine pebbles. Reaction of the profile is neutral or mildly alkaline throughout.
The A horizon has hue of 7.5YR or 10YR; value of 4 or 5 dry, 2 through 4 moist; and chroma of 2 through 4 dry, 2 or 3 moist. Clay content ranges from 12 to 20 percent. Pebbles range from 5 to 30 percent.
The Bt horizon has hue of 5YR to 10YR; value of 4 or 5 dry, 3 or 4 moist; and chroma of 4 through 6 dry, 2 through 4 moist. Texture typically is sandy clay loam or sandy loam with more than 35 percent fine sand or coarser. Clay content ranges from 17 to 25 percent. Rock fragment content ranges from 25 to 45 percent pebbles.
The C horizon has hue of 5YR or 7.5YR; value of 4 or 5 dry, 3 or 4 moist; and chroma of 4 through 6 dry and moist. Texture typically is sandy loam or loamy sand with a clay content of 5 to 10 percent. Rock fragment content ranges from 40 to 80 percent pebbles. This horizon may be absent in some pedons.
COMPETING SERIES: These are the Whiteman series in the same family and the Rogert and Redfeather series. Whiteman soils lack the coarse granitic sands and formed in residuum from limestone. Rogert soils have mollic epipedons and do not have argillic horizons. Redfeather soils, when mixed to a depth of 6 inches, have a moist color value of 4 or more.
GEOGRAPHIC SETTING: Hapjack soils are on nearly level to very steep uplands and mountainsides. Slopes are 3 to 50 percent. These soils formed in residuum and colluvium from granite. Elevation is 7,800 to 9,500 feet. The mean annual precipitation is about 17 inches and ranges from 15 to 19 inches. The mean annual temperature is 39 degrees F. and ranges from 38 to 40 degrees F. The frost-free season is less than 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Rogert and Redfeather series and the Amesmont series. Amesmont soils have granite bedrock at 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff on gentler slopes and rapid runoff on steeper slopes; moderate permeability.
USE AND VEGETATION: These soils are used principally for rangeland and recreation. Vegetation is mostly bluebunch wheatgrass, needleandthread, Idaho fescue, and threetip sagebrush.
DISTRIBUTION AND EXTENT: The mountains of southeastern Wyoming. The series is of moderate extent, covering about 30,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Albany County, (Albany County Area), Wyoming; 1991. The name is taken from a nearby recreation area.
REMARKS: Diagnostic horizons recognized in this pedon are:
Ochric epipedon--0 to 3 inches (A)
Argillic horizon--3 to 10 inches (Bt)
Lithic contact--19 inches (R)