LOCATION BOULDROCK OR

Established Series
Rev. GDM/TDT
06/2011

BOULDROCK SERIES

The Bouldrock series consists of moderately deep, well drained soils on mountainous areas. They formed in colluvium and residuum derived dominantly from quartz diorite. Slope is 12 to 80 percent. The mean annual precipitation is about 18 inches, and the mean annual temperature is about 42 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Humic Haploxerepts

TYPICAL PEDON: Bouldrock loam - on a 32 percent south-facing slope, rangeland. (Colors are for moist soil unless otherwise noted.)

A--0 to 6 inches; black (10YR 2/1) loam, dark grayish brown (10YR 4/2) dry; weak fine and medium subangular blocky structure parting to weak fine granular; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine irregular pores; 5 percent gravel; neutral (pH 6.8); clear smooth boundary. (4 to 7 inches thick)

Bw1--6 to 15 inches; very dark brown (10YR 2/2) sandy loam, dark grayish brown (10YR 4/2) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine continuous tubular pores; neutral (pH 6.6); clear smooth boundary. (6 to 13 inches thick)

Bw2--15 to 21 inches; very dark grayish brown (10YR 3/2) sandy loam, dark brown (10YR 3/3) dry; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine continuous tubular pores; neutral (pH 6.6); gradual smooth boundary. (5 to 12 inches thick)

C--21 to 32 inches; dark brown (10YR 3/3) sandy loam, brown (10YR 4/3) dry; massive; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine discontinuous tubular pores; slightly acid (pH 6.4); gradual wavy boundary. (5 to 10 inches thick)

Cr--32 inches; highly weathered quartz diorite.

TYPE LOCATION: Baker County, Oregon; located 1,300 feet north and 600 feet west of the SW corner of sec. 14, T. 13 S., R. 42 E.

RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry in the moisture control section for 50 to 80 consecutive days following the summer solstice. The mean annual soil temperature is 43 to 47 degrees F. Depth to bedrock is 20 to 40 inches. Organic carbon ranges from 0.3 to 0.60 in the upper 24 inches.

The A horizon has value of 2 or 3 moist, 4 or 5 dry and chroma of 1 through 3 moist and dry. It is loam or very bouldery loam. It has 0 to 10 percent gravel, 0 to 10 percent cobbles, 0 to 30 percent stones and 0 to 30 percent boulders.

The Bw horizon has value of 2 or 3 moist, 4 or 5 dry and chroma of 2 or 3 moist and dry. It is loam or sandy loam. It has 0 to 15 percent gravel.

The C horizon has chroma of 3 or 4 moist and dry. It is sandy loam or loamy sand, with 0 to 20 percent gravel.

COMPETING SERIES: These are the Labuck, Stapaloop, Stavely and Switchback series. Labuck and Switchback soils have light colored epipedons. Stapaloop and Stavely soils are more than 40 inches deep to bedrock.

GEOGRAPHIC SETTING: Bouldrock soils are on south-facing side slopes of mountainous areas. Elevations range from 4,000 to 6,200 feet. Slope is 12 to 80 percent. The soil formed in colluvium and residuum derived dominantly from quartz diorite. The mean annual precipitation is 16 to 20 inches. The mean annual temperature is 40 to 45 degrees F. The frostfree period is 70 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kilmerque, Dogtown and Taterpa soils. Kilmerque soils are on adjacent forested south slopes. Dogtown soils are deep, loamy-skeletal soils on adjacent forested north slopes. Taterpa soils are deep and are on adjacent north slopes.

DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium to rapid. Permeability is moderate in the surface horizons and moderately rapid in the subsoil.

USE AND VEGETATION: These soils are used for rangeland. The native vegetation is bluebunch wheatgrass, mountain big sagebrush, arrowleaf balsamroot and gray rabbitbrush.

DISTRIBUTION AND EXTENT: Eastern Oregon; MLRA 10. The series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Baker County Area, Oregon; 1988.

REMARKS: Diagnostic horizons and features in this pedon are:

Ochric epipedon - the zone from the surface of the soil to a depth of approximately 6 inches (A horizon); organic carbon
is less than 0.6 percent throughout.
Cambic horizon - the zone from 6 to 21 inches (Bw1, Bw2 horizons).
Humic subgroup - the color of the A and B horizon meets humic subgroup criteria

ADDITIONAL DATA: Lincoln Lab samples 85Q1916-1917; samples are from the same general area as the typical pedon
described here.

National Cooperative Soil Survey
U.S.A.