LOCATION RAINBOLT           WY
Established Series
Rev.CHP/PSD/MCS
02/1999

RAINBOLT SERIES


The Rainbolt series consists of well drained soils that are moderately deep to weakly consolidated sandstone. They formed in alluvium derived from mixed granitic and sedimentary sources. Rainbolt soils are on pediment slopes below granite hills and mountains. Slopes range from 3 to 25 percent. The mean annual precipitation is about 12 inches, and the mean annual temperature is about 39 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive Ustic Argicryolls

TYPICAL PEDON: Rainbolt gravelly sandy loam on a southeast- facing 4 percent slope on rangeland. (Colors are for dry soil unless otherwise stated.) The surface has 15 percent pebbles.

A--0 to 2 inches; brown (7.5YR 5/3) gravelly sandy loam, dark brown (7.5YR 3/2) moist; moderate fine and medium granular structure; soft, very friable, slightly sticky and nonplastic; many fine roots; many very fine continuous pores; 20 percent pebbles; mildly alkaline (pH 7.4); abrupt smooth boundary. (1 to 3 inches thick)

Bt1--2 to 9 inches; dark brown (7.5YR 4/3) gravelly sandy clay loam, dark brown (7.5YR 3/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; many fine roots; common very fine continuous pores; few thin clay films on faces of peds; 20 percent pebbles; moderately alkaline (pH 8.0); clear smooth boundary.

Bt2--9 to 16 inches; reddish brown (2.5YR 4/4) gravelly sandy clay loam, reddish brown (2.5YR 4/3) moist; moderate medium subangular blocky structure; hard, friable, sticky and slightly plastic; common fine roots; common very fine continuous pores; common moderately thick clay films on faces of peds; slightly effervescent, lime disseminated; 25 percent pebbles; moderately alkaline (pH 8.1); clear smooth boundary. (Combined thickness of the Bt is 12 to 22 inches.)

Bk--16 to 28 inches; reddish brown (2.5YR 4/4) sandy clay loam, dark reddish brown (2.5YR 3/4) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine roots; strongly effervescent, carbonates disseminated and as common fine and medium small masses; 10 percent pebbles; strongly alkaline (pH 8.6); clear smooth boundary. (10 to 16 inches thick)

Cr--28 inches; coarse grained; weakly consolidated reddish sandstone.

TYPE LOCATION: Albany County, Wyoming; about 2,325 feet east and 1,100 feet north of the SW corner of sec. 32, T. 13 N., R. 76 W.

RANGE IN CHARACTERISTICS: Depth to bedrock ranges from 20 to 40 inches. The mean annual soil temperature ranges from 35 to 45 degrees F., and the mean summer soil temperature ranges from 50 to 59 degrees F. Ten to 20 percent of the surface is covered with granitic pebbles. Depth to the base of the mollic epipedon ranges from 7 to 10 inches. Depth to the base of the argillic horizon ranges from 16 to 27 inches. This soil contains few to common mica flakes throughout.

The A horizon has hue of 5YR through 10YR, value of 3 through 5 dry and moist, and chroma of 2 or 3 dry and moist. Texture is commonly gravelly sandy loam but the range includes sandy loam. Reaction is mildly or moderately alkaline. Coarse fragments range from 10 to 20 percent pebbles.

The Bt horizon has hue of 2.5YR through 7.5YR, value of 3 through 5 dry, 3 or 4 moist, and chroma of 3 or 4 dry and moist. Texture is commonly gravelly sandy clay loam, but the range includes sandy clay loam and clay loam. Clay ranges from 20 to 35 percent with more than 35 percent fine or coarser sand. The reaction is moderately or strongly alkaline. Coarse fragments range from 5 to 25 percent pebbles.

The Bk horizon has hue of 2.5YR or 7.5YR and value of 4 through 6 dry and 3 or 4 moist. Texture is sandy clay loam or clay loam. The reaction is moderately or strongly alkaline. Coarse fragments range from 0 to 10 percent pebbles.

COMPETING SERIES: These are the Amsden, Buffork, Cific, Coldspring (T) CO, Croftshaw, Croyden, Dra, Gebson, Gelkie, Hourglass, Inchau, Kezar, Kittredge, Leavitt, Lucky, Lymanson, Lyonman, Michelson, Miracle, Monad, Monida(T) ID Morset, Mult, Newlands, Oro Fino, Passcreek, Philipsburg, Primeaux, Rammel, Shotgun, Slacks(T) ID, Sponsar(T)CO,
Swede, Tingey, Tripit, Troutdale, Wellsville, Woosley, and Youga. Amsden, Coldspring, Croftshaw, Croyden,Gebson, Gelkie, Hourglass, Kittredge, Leavitt, Lyonman, Michelson, Monad,Monida, Morset,Oro Fino, Philipsburg, ,Swede, Tingey, Wellsville, and Youga soils are deeper than 40 inches. Buffork, Inchau, Kezar, Lucky, Miracle, Mult, Newlands, Sponsor, Swede, and Troutdale soils are noncalcareous. Cific soils formed in glacial drift over shale and have a lithologic discontinuity above the bedrock. Dra, Passcreek, Primeaux, Rammel,Shotgun, Slacks, and Woosley soils have a lithic contact. Lymanson soils are 7.5YR or browner throughout. Tripit soils have less than 35 percent fine or coarser sand and have no mica in the profile.

GEOGRAPHIC SETTING: Rainbolt soils are on pediment slopes below granite hills and mountains. They formed in alluvium from mixed granitic and sedimentary sources. Slopes range from 3 to 25 percent. Elevation is 7,400 to 8,200 feet. The mean annual precipitation ranges from 12 to 17 inches. The mean annual temperature ranges from 39 to 45 degrees F. The frost-free season is 60 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hapjack, the competing Kezar, and the Rawah soils. Hapjack soils are shallow. Rawah soils are nonmollic.

DRAINAGE AND PERMEABILITY: Well drained; runoff is medium or rapid; permeability is moderately rapid.

USE AND VEGETATION: Rangeland, wildlife habitat, and recreation. Native vegetation consists of western wheatgrass, bluebunch wheatgrass, needleandthread, and some Idaho fescue and sagebrush.

DISTRIBUTION AND EXTENT: Foothills of southeastern Wyoming. The series is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Albany County (Albany County Area), Wyoming; 1991. The name is coined.

REMARKS: Diagnostic horizons recognized in this soil are:

Mollic epipedon--0 to 9 inches. (A,Bt1)

Argillic horizon--2 to 16 inches. (Bt1, Bt2)


National Cooperative Soil Survey
U.S.A.