LOCATION HOBOHILL                WA

Established Series
Rev. SP/RJE/TLA
01/2023

HOBOHILL SERIES


The Hobohill series consists of deep, somewhat excessively drained soils formed in glacial outwash and alluvium on fan terraces, old alluvial fans, and terrace escarpment. Slope is 3 to 70 percent. The average annual precipitation is about 14 inches, and the mean annual temperature is about 48 degrees F.

TAXONOMIC CLASS: Sandy, mixed, mesic Ultic Haploxerolls

TYPICAL PEDON: Hobohill sandy loam - on a northeast facing 68 percent slopes, at 2,400 feet elevation. (Colors are for dry soil unless otherwise stated.)

A1--0 to 3 inches; dark grayish brown (10YR 4/2) sandy loam, black (10YR 2/1) moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; many very fine and fine roots; 10 percent pebbles; neutral (pH 6.6); clear wavy boundary.

A2--3 to 18 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; common very fine and fine roots; 10 percent pebbles; neutral (pH 6.8); clear smooth boundary. (Combined thickness of A horizon is 10 to 18 inches)

C1--18 to 30 inches; pale brown (10YR 6/3) gravelly loamy sand, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky, nonplastic; few very fine and fine roots; 15 percent pebbles; neutral (pH 7.2); gradual smooth boundary. (10 to 48 inches thick)

C2--30 to 60 inches; light gray (2.5Y 7/2) gravelly sand, grayish brown (2.5Y 5/2) moist; massive; soft, very friable, nonsticky, nonplastic; few very fine roots; 25 percent pebbles; neutral (pH 7.3).

TYPE LOCATION: Okanogan County, Washington; about 5 miles southeast of Nespelem; 1,000 feet north and 1,000 feet west of the southeast corner of sec. 10, T. 30 N., R.31E, W.M.

RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches ranges from 49 to 51 degrees F. These soils are usually moist but are dry in all parts of the moisture control section for 90 to 105 consecutive days following the summer solstice. The mollic epipedon is 10 to 20 inches thick. The particle-size control section averages 10 to 30 percent rock fragments. Reaction is slightly acid or neutral.

The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 1 or 2 moist. It is 0 to 15 percent pebbles in the upper part and 10 to 25 percent pebbles in the lower part. Some pedons are stony and have 0.1 to 3 percent surface stones and boulders and 0 to 5 percent surface cobbles.

Some pedons have a weakly expressed Bw horizon.

The C horizon has hue of 10YR or 2.5Y, value of 6 or 7 dry, 5 or 6 moist, and chroma of 2 or 3 dry or moist. The upper part is sand, gravelly loamy sand, or gravelly loamy coarse sand. It is 10 to 25 percent pebbles, and 0 to 5 percent cobbles. The lower part ranges from loamy coarse sand to coarse sand and commonly is gravelly and less commonly very gravelly. It is 20 to 35 percent pebbles and 0 to 5 percent cobbles.

COMPETING SERIES: These are the Battleplain, Cave Rock (T), and closely related Haley series. Battleplain soils are dry in the moisture control section for 75 to 90 consecutive days following the summer solstice. Cave Rock soils are sandy throughout and have a mollic epipedon 24 to 36 inches thick. Haley soils are coarse-loamy over sandy or sandy-skeletal.

GEOGRAPHIC SETTING: Hobohill soils formed in glacial outwash and alluvium on fan terraces, old alluvial fans, and terrace escarpments. Elevation ranges from 1,400 to 2,500 feet. Slope is 3 to 70 percent. These soils are in a climate with warm, dry summers and cool, moist winters. The average annual precipitation is 12 to 15 inches. The mean January temperature is 25 degrees F, the mean July temperature is 71 degrees F, and the mean annual temperature is 47 to 49 degrees F. The frost-free season is 110 to 150 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Conconully, Ewall, Nespelem, Owhi, Picard, and the competing Battleplain and Haley soils. Conconully and Picard soils are coarse-loamy. Ewall soils have an ochric epipedon and are sandy throughout. Nespelem soils are coarse-silty and calcareous in the particle-size control section. Owhi soils are coarse-loamy and have sandy-skeletal material in the lower part of the particle-size control section.

DRAINAGE AND PERMEABILITY: Well drained; slow to very rapid runoff; moderately rapid permeability.

USE AND VEGETATION: Native range, wildlife habitat, and watershed. Vegetation is bluebunch wheatgrass, needleandthread, Sandberg bluegrass, Idaho fescue, arrowleaf balsamroot, hood phlox, silky lupine, antelope bitterbrush, and threetip sagebrush.

DISTRIBUTION AND EXTENT: Northeastern Washington. The series is of small extent.

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

SERIES ESTABLISHED: Colville Indian Reservation, Okanogan County, Washington, 1987.

REMARKS: Diagnostic horizons and features recognized in this soil are a mollic epipedon from the mineral surface to 18 inches, and a particle-size control section that averages 17 percent pebbles. Hobohill soils were previously called the Beckley series on the Colville Indian Reservation. Beckley soils are Typic Haploxerolls, but laboratory data on other soils in the same climatic zone suggest that Hobohill soils are Ultic Haploxerolls.


National Cooperative Soil Survey
U.S.A.