LOCATION BOWLUS OREstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Pachic Ultic Haploxerolls
TYPICAL PEDON: Bowlus silt loam, rangeland. (Colors are for moist soil unless otherwise noted.)
A1--0 to 8 inches; black (10YR 2/1) silt loam, very dark gray (10YR 3/1) dry; strong fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, fine and medium roots; common coarse roots; many very fine irregular pores; neutral (pH 7.0); gradual wavy boundary. (6 to 15 inches thick)
A2--8 to 19 inches; black (10YR 2/1) silt loam, very dark grayish brown (10YR 3/2) dry; strong fine subangular blocky structure parting to strong fine and medium granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, fine and medium roots and common coarse roots; common very fine tubular pores; neutral (pH 7.0); gradual wavy boundary. (10 to 20 inches thick)
AB--19 to 42 inches; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, fine and medium roots and common coarse roots; common very fine tubular pores; neutral (pH 6.6); gradual wavy boundary. (10 to 25 inches thick)
2Bw--42 to 60 inches; dark brown (10YR 3/3) very cobbly silty clay loam, yellowish brown (10YR 5/4) dry; moderate very fine and fine angular blocky structure; hard, friable, sticky and plastic; common very fine and fine roots, few medium and coarse roots; common very fine tubular pores; 20 percent cobbles, 30 percent gravel; neutral (pH 7.2).
TYPE LOCATION: Umatilla County, Oregon, in the NE1/4 SE1/4 NW1/4 section 1, T. 1 N., R. 33 E.
RANGE IN CHARACTERISTICS: The soils are usually moist, but they are dry throughout between depths of 4 to 12 inches for 60 to 80 consecutive days following the summer solstice. The mean annual soil temperature is 43 to 47 degrees F. Depth to basalt is greater than 60 inches. Depth to the 2Bw horizon is 40 to 60 inches. Thickness of the mollic epipedon is 20 to 30 inches. The textural control section averages 20 to 35 percent clay. It has less than 15 percent coarser than very fine sand.
The A horizon has chroma of 1 or 2 when dry. It is slightly acid or neutral.
The AB horizon has value of 2 or 3 when moist and chroma of 2 or 3 when dry. It is a silt loam or silty clay loam. It is slightly acid or neutral.
The 2Bw horizon has hue of 10YR or 7.5YR and value of 2 through 4 when moist and dry. It is silty clay loam, cobbly silty clay loam or very cobbly silty clay loam. It has 0 to 30 percent gravel and 0 to 30 percent cobbles. It is moderately acid or neutral.
COMPETING SERIES: There are no other soils in this family. The Carlton and Palouse soils are in a similar family. These soils have a mesic soil temperature regime.
GEOGRAPHIC SETTING: Bowlus soils are on steep north facing slopes at elevations of 2,000 to 3,800 feet. Slopes are 40 to 70 percent. The soils formed in loess and basalt residuum mixed with small amounts of volcanic ash. The mean annual temperature is 41 to 45 degrees F., and the mean annual precipitation is 20 to 30 inches. The frost-free period is 60 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buckcreek, Gurdane, Gwin, Gwinly, Kahler, Rockly, Tolo, Umatilla and Waha soils. Gwin, Gwinly and Rockly soils are less than 20 inches deep. Gurdane soils are clayey-skeletal and 20 to 40 inches deep. Kahler soils are fine-loamy. Tolo soils are medial over loamy. Umatilla and Buckcreek soils are loamy-skeletal. Waha soils are fine-loamy and 20 to 40 inches deep.
DRAINAGE AND PERMEABILITY: Well drained; very rapid runoff; moderate permeability.
USE AND VEGETATION: Bowlus soils are used for wildlife habitat and range. Native vegetation is ninebark, snowberry, rose, Idaho fescue and scattered coniferous and deciduous trees.
DISTRIBUTION AND EXTENT: Along the foothills of the Blue Mountains in northeastern Oregon. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Umatilla County, Oregon, 1983.