LOCATION COPENHAVER         MT

COPENHAVER SERIES

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Lithic Argicryolls

TYPICAL PEDON: Copenhaver gravelly loam in grassland (colors are for dry unless otherwise noted).

A--0 to 5 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; many fine and very fine roots, many very fine pores; 25 percent pebbles; neutral (pH 7.2); clear smooth boundary. (4 to 7 inches thick)

Bt--5 to 14 inches; reddish brown (5YR 4/3) very gravelly clay loam, dark reddish brown (5YR 3/3) moist; weak fine subangular blocky structure; very hard, friable, slightly sticky and moderately plastic; many fine and very fine roots, many fine and very fine pores; few faint clay films on faces of peds and on coarse fragments; 10 percent cobbles, 40 percent pebbles; slightly alkaline (pH 7.6) clear smooth boundary. (6 to 12 inches thick)

R--14 inches; andesite bedrock.

TYPE LOCATION: Powell County, Montana; 250 feet south and 350 feet east of the NW corner of sec. 15, T. 8 N., R. 8 W.

RANGE IN CHARACTERISTICS:

Soil temperature - 36 to 41 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 16 inches.
Depth to bedrock - 10 to 20 inches.
Surface stones or boulders - 0 to 0.1 percent

A horizon
Hue: 10YR, 7.5YR, or 5YR
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 2 or 3
Clay content: 18 to 27 percent
Rock fragments: 15 to 70 percent--0 to 10 percent stones; 0 to 20 percent cobbles or flagstones; 15 to 40 percent pebbles or channers
Reaction: pH 6.1 to 7.3

Bt horizon
Hue: 10R, 2.5YR, 5YR or 7.5YR
Value: 4, 5 or 6 dry; 3 or 4 moist
Chroma: 2, 3, 4, or 6
Texture: loam, sandy clay loam or clay loam
Clay content: 20 to 35 percent
Rock fragments: 35 to 80 percent--5 to 20 percent cobbles; 30 to 60 percent pebbles
Reaction: pH 6.1 to 7.8

COMPETING SERIES:

Bushpark (CO) - has an udic moisture regime.

Donkehill (T)(ID) - has a xeric moisture regime.

Hogmalat (ID) - has a xeric moisture regime.

Layview (NV) - has a mean annual soil temperature of 43 to 47 degrees F.

Maygal (NV) - has a xeric moisture regime.

Mosroc (WY) - dry in the moisture control section in the months of June, July, and August; precipitation of 10 to 14 inches; at elevations of 7,000 feet and higher.

Mountpatterson (CA) - has a xeric moisture regime.

Nielsen (ID) - has a xeric moisture regime.

Nieman (MT) - does not have hues redder than 10YR in the argillic horizon.

Notstew (T)(NV) - has a xeric moisture regime.

Thiefridge (CA) - has a xeric moisture regime.

GEOGRAPHIC SETTING:
Landform - hills; mountains.
Elevation - 5,200 to 8,600 feet.
Slope - 4 to 60 percent
Parent material - materials weathered from mixed rock sources.
Climate - long, cold winters; moist springs; cool summers.
Mean annual precipitation - 15 to 25 inches, most of which falls during spring and early in summer.
Mean annual air temperature - 34 to 39 degrees F.
Frost-free period - 30 to 70 days.

GEOGRAPHICALLY ASSOCIATED SOILS:

DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.

USE AND VEGETATION: Copenhaver soils are used mainly for rangeland. Potential native vegetation is mainly rough fescue, Idaho fescue, lupine, bluebunch wheatgrass, prairie junegrass, western yarrow, and hoods phlox.

DISTRIBUTION AND EXTENT: The Copenhaver series is not extensive in western Montana. MLRA 43B.

MLRA OFFICE RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Powell County, Montana, 1995.

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from the soil surface to 14 inches (A, Bt horizons).
Argillic horizon - from 5 to 14 inches (Bt horizon).
Particle-size control section - from the soil surface to 14 inches (A, Bt horizon).
Lithic contact - 14 inches (R horizon).

Copenhaver soils have a cryic temperature regime and an ustic moisture regime.

Soil interpretation record: MT1214, MT1413.