LOCATION ROTTULEE MT+UTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Entic Haplustolls
TYPICAL PEDON: Rottulee silt loam, grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 2 inches; dark-brown (7.5YR 4/2) silt loam, dark brown (7.5YR 3.2) when moist; weak, thin, platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots and tubular pores; moderately calcareous; clear, smooth boundary. (2 to 5 inches thick)
B1--2 to 6 inches; reddish-brown (5YR 5/3) silt loam, dark reddish brown (5YR 3/3) when moist; weak, medium, prismatic structure; slightly hard, very friable, slightly sticky and plastic; common very fine roots; common fine and very fine tubular pores; moderately calcareous; clear, wavy boundary. (2 to 6 inches thick)
B2--6 to 10 inches; light reddish-brown (5YR 6/3) heavy silt loam, reddish brown (5YR 4/4) when moist; moderate, medium, prismatic structure; hard, friable, sticky and plastic; common very fine roots; common fine and very fine tubular pores; moderately calcareous; clear, wavy boundary. (3 to 7 inches thick)
B3--10 to 15 inches; light reddish-brown (5YR 6/3) heavy silt loam, reddish brown (5YR 4/4) when moist; moderate, medium and fine, blocky structure; hard, friable, sticky and plastic; common very fine roots and tubular pores; strongly calcareous with a few threads of segregated lime; clear, wavy boundary. (4 to 8 inches thick)
Cca--15 to 22 inches; light reddish-brown (5YR 6/4) gravelly light clay loam, yellowish red (5YR 5/6) when moist; weak, fine, blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine roots and tubular pores; 20 percent (volume) shale fragments; strongly calcareous; common fine threads of segregated lime; gradual boundary.
R--22 inches, shattered limestone.
TYPE LOCATION: Big Horn County, Montana; 660 feet north and 220 feet east of the SW corner of sec. 18, T.8S., R.33E.
RANGE IN CHARACTERISTICS: The control section is silt loam, loam, light silty clay loam, or light clay loam with 20 to 34 percent clay and 15 to 25 percent fine or medium sand and with gravel-size shale fragments increasing to as much as 30 percent just above the bedrock. The soil is weakly to strongly calcareous with increasing quantity of lime with increased depth above the bedrock. The soil has hue of 7.5YR through 10R. Mean annual soil temperature ranges from 44 to 47 degrees F., and average summer soil temperature ranges from 59 to 65 degrees F.
The Cca horizon has few to common films and threads of lime or few masses of accumulated flour lime. It contains 8 to 15 percent (estimated) CaC03 equivalent.
COMPETING SERIES: These are the Amor, Bynum, Darret, Duffy, Max, Peritsa, Prospect, Quigley, Searing, Shambo and Twin Creek series. Amor and Peritsa soils have a paralithic contact at depths of 20 to 40 inches. Bynum soils have average summer soil temperature of 52 to 58 degrees F. and have hue of 10YR or 2.5Y. Darret soils have an argillic horizon. Duffy, Max, Prospect and Quigley soils have hue of 10YR through 5Y. Max, Prospect, Quigley, Shambo and Twin Creek soils lack bedrock within depth of 40 inches. Searing soils are noncalcareous to depths of 10 to 24 inches.
GEOGRAPHIC SETTING: Rottulee soils are on gently to strongly rolling red shale and limestone bedrock uplands at elevations of 4,500 to 5,500 feet. The climate is dry-subhumid with mean annual precipitation of 17 to 19 inches, 80 percent of which falls in April through October. The annual temperature ranges from 40 to 45 degrees F. and the mean summer temperature ranges from 55 to 65 degrees F. The frost-free season ranges from 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Abac soils and the competing Peritsa and Twin Creek soils. Abac soils have sandstone at depths shallower than 20 inches.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderate permeability.
USE AND VEGETATION: Native range use. Native vegetation is phlox, green needlegrass, prairie junegrass, gayfeather, and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: South-central Montana. The Rottulee series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Big Horn County (Big Horn Area), Montana, 1970.
REMARKS: The Rottulee soils were formerly classified as Chestnut soils.
OSED scanned by SSQA. Last revised by state on 8/74.