LOCATION PROSPECT MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Haplustolls
TYPICAL PEDON: Prospect stony loam. (Colors are of dry soil unless otherwise noted.)
A1--0 to 2 inches; dark gray (10YR 4/1) stony loam, very dark brown (10YR 2/2) moist; weak fine platy and fine crumb structure; soft, very friable; neutral; clear boundary. (1 to 3 inches thick)
A2--2 to 6 inches; dark gray (10YR 4/1) stony loam, very dark brown (10YR 2/2) moist; weak to moderate fine granular structure; soft, very friable; neutral; clear irregular boundary. (3 to 5 inches thlck)
Bw1--6 to 11 inches; grayish brown (10YR 5/2) stony silt loam; very dark grayish brown (10YR 3/2) moist; weak medium and coarse prismatic separating to weak to moderate medium blocky structure; soft, friable, slightly sticky, slightly plastic; clear boundary. (4 to 8 inches thick)
Bw2--11 to 14 inches; light brownish gray (10YR 6/2) stony silt loam, dark grayish brown (10YR 4/2) moist; weak medium and coarse prismatic separating to moderate medium blocky structure; soft, very friable; neutral reaction; abrupt irregular lower boundary. (2 to 4 inches thick)
Bk--14 to 24 inches; pale yellow (2.5Y 8/2) stony and gravelly silt loam, light brownish gray (2.5Y 6/2) moist; weak coarse and medium subangular blocky structure; slightly firm in place but loose and very friable when disturbed; strongly calcareous with a large amount of soft floury segregated lime carbonate; clear boundary. (8 to 12 inches thick)
C--24 to 30+ inches; light gray, friable, calcareous, stony gravelly loam till.
TYPE LOCATION: Flathead County, Montana; 1/4 mile west and 600 feet north of SE corner of Section 28, T29N, R22W.
RANGE IN CHARACTERISTICS: Chiefly in the thickness of the several horizons and the depth to free carbonates. On the steeper slopes the Cca horizon is no more than 10 or 12 inches below the surface. Loam and stony loam types are recognized. Some of the presently nonstony fields have had the large stones removed to facilitate tillage and harvesting operations.
COMPETING SERIES: These are the Amor, Azaar , Barnes, Diagulch, Doland, Edgeley, Formdale, Hilbar Max, Minnimaud, Peerless, Quigley, Shambo, Tansem, Teweel, Twin Creek, Vienna, and Yeoman series.
GEOGRAPHIC SETTING: Gently undulating to steep kettle and kane topography of lateral and recessional moraines. The Prospect series comprises Chestnut soils developed in light colored, medium textured calcareous glacial till in valleys in the Northern Rocky Mountains. The rocks in the till are quartzites, argillites and dolomitic limestones of the Belt geological formation. Although having a weaker degree of horizonation, the profile of the Prospect series resembles that of the Williams series, Chestnut soils of the glaciated Northern Great Plains, in kind and sequence of horizons and in lacking a textural B horizon, but the Prospect series has a more weakly developed structural B horizon and a greater and more diffused segregation of lime than in the Williams series. Also, the Prospect series is developed in a glacial till of hard rock sources that weather to a high proportion of silt relative to low amounts of sand fractions and clay, whereas in the Williams series the soil separates are more nearly of equal proportion. The Prospect series has lighter colored A and thinner A/B horizons than its Chernozem counterpart, the Yeoman series. The Prospect series is widely distributed throughout the Northern Rocky Mountain region, but is not extensive and is only of local importance in agriculture.
DRAINAGE AND PERMEABILITY: Well drained; permeability moderate; runoff is low to moderate, but is high on the steeper cultivated fields.
USE AND VEGETATION: Native and improved pastures; small grain chiefly grown in cultivated areas; alfalfa. Grasses are those common to the region and there are scattered ponderosa pine in places.
DISTRIBUTION AND EXTENT: Western Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Upper Flathead Valley Area, Montana, 1957.