LOCATION REDVALE MTEstablished Series
TAXONOMIC CLASS: Clayey over sandy or sandy-skeletal, smectitic, frigid Aridic Paleustalfs
TYPICAL PEDON: Redvale loam pasture. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 6 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; weak very thin platy structure; hard, friable, sticky and slightly plastic; common roots; neutral; abrupt smooth boundary. (4 to 7 inches thick)
B21t--6 to 11 inches; pale brown (10YR 6/3) light clay loam, dark grayish brown (10YR 4/2) moist; moderate medium prismatic structure that parts to weak thin platy; bleached silt and sand skeletans on faces of peds; hard, friable, sticky and slightly plastic; common roots; many very fine pores; neutral; abrupt smooth boundary. (2 to 6 inches thick)
B22t--11 to 20 inches; brown (2.5Y 5/3) light clay, dark grayish brown (2.5Y 4/2) moist; strong medium prismatic structure; very hard, firm, sticky and plastic; common roots; few very fine pores; thick continuous very dark grayish brown (10YR 3/2) moist clay films on faces of peds; neutral; clear smooth boundary. (8 to 15 inches thick)
B3ca--20 to 30 inches; light brownish gray (2.5Y 6/2) gravelly clay loam, dark grayish brown (2.5Y 4/2) moist; weak medium prismatic structure; hard, firm, sticky and plastic; common roots; common very fine pores; 25 percent pebbles; lime casts on lower side of pebbles; strongly effervescent with many distinct medium and fine white (2.5Y 8/2) soft masses of lime; moderately alkaline; gradual smooth boundary. (7 to 15 inches thick)
IIC--30 to 60 inches; pale brown (10YR 6/3) very gravelly loamy sand, dark brown (10YR 4/3) moist; single grained; loose, slightly sticky and nonplastic; few roots; 70 percent pebbles; thin lime casts on lower side of pebbles; strongly effervescent; moderately alkaline.
TYPE LOCATION: Valley County, Montana; 1,200 feet north and 2,300 feet west of the SE corner of section 18, T.30N., R.39E.
RANGE IN CHARACTERISTICS: The noncalcareous part of the solum is 15 to 24 inches thick. Depth to the very gravelly IIC horizon ranges from 20 to 40 inches. The mean annual soil temperature is 41 to 46 degrees F. The mean summer soil temperature is 63 to 69 degrees F.
The A horizon has hue of 10YR or 2.5Y, and chroma of 2 or 3.
The B2t horizon has hue of 10YR or 2.5Y, value of 5 or 6 dry, 3 or 4 moist, and chroma of 2 or 3. It is heavy clay loam or light clay and has 35 to 45 percent clay in the lower part.
The B3ca horizon, or upper part of the C horizon, contains 25 to 35 percent gravel. The IIC horizon contains 60 to 75 percent gravel. It is very gravelly loamy sand or very gravelly sand.
COMPETING SERIES: These are the Attewan, Phillips and Turner series. Attewan and Turner soils have mollic epipedons and have less than 35 percent clay in their B2t horizons. Phillips soils lack a sandy-skeletal C horizon.
GEOGRAPHIC SETTING: Redvale soils are nearly level and gently sloping and are mainly on alluvial fans and terraces. Elevations range from 2,000 to 3,500 feet. The soils formed in alluvium underlain by very gravelly loamy sand material. The climate is cool, dry-semiarid, and continental with cold dry winters and moist springs. Mean annual precipitation is 10 to 14 inches, most of which usually falls during spring and early summer. Mean annual temperature is 40 to 45 degrees F. Mean summer temperature is 64 to 71 degrees F. The freeze-free (32 degree F.) growing season is 110 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Absher Scobey and Thoeny soils and the competing Attewan and Phillips soils. These soils formed in glacial till and lack very gravelly C horizons.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately slow or slow permeability in the solum and rapid or very rapid in the substratum.
USE AND VEGETATION: Redvale soils are used for dryland crops, range and pasture. The native vegetation is mainly western wheatgrass, needleandthread, green needlegrass, bluebunch wheatgrass, prairie junegrass, Sandberg bluegrass, and forbs.
DISTRIBUTION AND EXTENT: Northern Plains of Montana and in western Colorado. It is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Western Colorado Reconnaissance Survey 1939.
REMARKS: The type location was shifted from Colorado to Montana in 1975.
OSED scanned by SSQA. Last revised by state on 10/76.