LOCATION MCGARR OR

Established Series
Rev. ED/AON
03/2013

MCGARR SERIES

The McGarr series consists of moderately deep, well drained soils that formed and basaltic or andesitic colluvium mixed with ash. McGarr soils are on mountains and hills and have slopes of 5 to 75 percent. The mean annual precipitation is about 22
inches, and the mean annual temperature is about 43 degrees F.

TAXONOMIC CLASS: Fine-loamy, isotic, frigid Vitrandic Haploxerolls

TYPICAL PEDON: McGarr stony ashy clay loam, forested. (Colors are for moist soil unless otherwise noted.)

Oi--0 to 1 inch; slightly decomposed fir needles and twigs.

A1--1 to 3 inches; very dark brown (10YR 2/2) stony ashy clay loam, dark grayish brown (10YR 4/2) dry; strong fine granular structure; soft, very friable, moderately sticky and moderately plastic; many very fine roots; 15 percent stones, 10 percent cobbles, 5 percent gravel; neutral (pH 6.6) abrupt smooth boundary. (2 to 6 inches thick)

A2--3 to 12 inches; very dark brown (10YR 2/2) stony ashy clay loam, dark grayish brown (10YR 4/2) dry; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine roots; many very fine tubular pores; 10 percent stones, 10 percent cobbles, 5 percent gravel; slightly acid (pH 6.4); clear smooth boundary. (6 to 12 inches thick)

Bw1--12 to 20 inches; very dark grayish brown (10YR 3/2) ashy clay loam, brown (10YR 4/3) dry; moderate medium and fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine roots; many very fine tubular pores; 5 percent cobbles and 5 percent gravel; slightly acid (pH 6.2); clear smooth boundary. (6 to 12 inches thick)

Bw2--20 to 27 inches; dark brown (10YR 3/3) cobbly ashy clay loam, brown (10YR 4/3) dry; strong medium and fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine roots; many very fine tubular pores; 10 percent cobbles and 10 percent gravel; slightly acid (pH 6.2); abrupt wavy boundary. (5 to 10 inches thick)

2R--27 inches; basalt.

TYPE LOCATION: Grant County, Oregon; 75 feet south of U.S. Highway 395, 95 yards east of milepost 94, 3 1/2 miles south of the town of Long Creek; 2,600 feet north and 600 feet west of the SE corner of Section 21, T. 10 S., R. 30 E. Latitude 44 degrees, 41 minutes, 05 seconds North, Longitude 119 degrees, 06 minutes, 18 seconds West.

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 42 to 47 degrees F. These soils are usually moist but are dry throughout between depths of 4 and 12 inches for 60 to 80 consecutive days during the summer. The solum is slightly acid to neutral. Depth to lithic contact is 20 to 40 inches. Thickness of the mollic epipedon is 20 to 30 inches. The solum has hue of 10YR or 7.5YR. The solum has 5 to 10 percent glass and ac id oxalate extractable aluminum plus one-half the iron is 0.4 to 0.8 percent.

The A horizon has value of 2 or 3 moist and 4 or 5 dry and chroma of 2 or 3 moist and dry. It contains 10 to 20 percent stones, 10 to 15 percent cobbles, and 5 to 15 percent gravel. Base saturation by sum is 65 to 75 percent.

The Bw horizon has value of 2 through 4 moist, 4 or 5 dry and chroma of 2 through 4 moist and dry. It is ashy clay loam, ashy loam or ashy silty clay loam wilth 25 to 35 percent clay. It has 5 to 15 percent cobbles and 5 to 15 percent gravel..

COMPETING SERIES: These are the Buford, Derr, Hall Ranch, Highvalley, Kahler, Minam and Myzel series. Buford soils are deep to bedrock. Derr soils contain rock fragments comprised of shale. Hall Ranch soils are moderately deep to a paralithic contact. Highvalley, Minam and Myzel soils are very deep. Kahler soils are deep and very deep to bedrock.

GEOGRAPHIC SETTING: McGarr soils are on mountains and hills at elevations of 3,000 to 5,800 feet. Slopes are 5 to 75 percent. They formed in loess and basaltic or andesitic colluvium. The climate is subhumid with a mean annual precipitation of 16 to 30 inches. The mean annual temperature is about 43 degrees F, mean July temperature is about 63 degrees F, and the mean January temperature is about 25 degrees F. The frost-free period is 30 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Anatone, Hankins, Klicker, Tolo and Top soils and the competing Hall Ranch and Kahler soils. Anatone soils have a lithic contact at depths of 10 to 20 inches. Hankins and Top soils have argillic horizons and are deeper than 40 inches to a lithic contact. Tolo soils are ashy over loamy. Klicker soils are loamy-skeletal.

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

USE AND VEGETATION: Timber production with some grazing. Vegetation is mainly Douglas fir and ponderosa pine with an understory of pinegrass and elk sedge.

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

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

SERIES ESTABLISHED: Grant County, Oregon; 1975.

REMARKS: Diagnostic horizons and other features:

Mollic epipedon - 0 to 27 inches
Ultic - the A horizon has base saturation of less than 75 percent throughout.

ADDITIONAL DATA: S97OR-023-026.

National Cooperative Soil Survey
U.S.A.