LOCATION MCEWEN OREstablished Series
TAXONOMIC CLASS: Fine-loamy, isotic, frigid Vitrandic Haploxeralfs
TYPICAL PEDON: McEwen ashy silt loam - woodland. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inch; partially decomposed litter layer of needles, leaves and twigs.
A--1 to 5 inches; dark brown (7.5YR 3/2) ashy silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium roots; many very fine tubular pores; neutral (pH 6.6); abrupt smooth boundary. (2 to 8 inches thick)
AB--5 to 13 inches; dark brown (7.5YR 3/4) ashy silt loam, pale brown (10YR 6/3) dry; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium roots; many very fine tubular pores; neutral (pH 6.6); clear smooth boundary. (0 to 10 inches thick)
2Bt1--13 to 19 inches; dark brown (7.5YR 3/4) clay loam, light brown (7.5YR 6/4) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common roots; many very fine tubular pores; few faint reddish brown (5YR 4/4) clay films on faces of peds and in pores; neutral (pH 6.6); clear smooth boundary. (4 to 12 inches thick)
2Bt2--19 to 31 inches; dark reddish brown (5YR 3/4) clay loam, reddish brown (5YR 5/3) dry; moderate medium subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common roots; common very fine tubular pores; common faint and few distinct reddish brown (5YR 4/4) clay films on faces of peds and in pores; neutral (pH 6.6); clear smooth boundary. (8 to 16 inches thick)
2Bt3--31 to 44 inches; dark reddish brown (5YR 3/4) clay loam, reddish brown (5YR 5/3) dry; weak medium subangular blocky structure; hard, firm, sticky and plastic; common roots; common fine to coarse pores; few faint reddish brown (5YR 4/4) clay films on ped faces and in pores; 10 percent gravel; few fine black concretions and stains; neutral (pH 6.6); clear smooth boundary. (8 to 14 inches thick)
3C--44 to 60 inches; dark reddish brown (5YR 3/4) extremely gravelly loam, light reddish brown (5YR 6/4) dry; massive; loose, friable, slightly sticky and slightly plastic; few roots; 50 percent gravel and 10 percent cobbles; neutral (pH 6.8).
TYPE LOCATION: Baker County, Oregon; 900 feet north, 800 feet east of the SW corner of sec. 8, T. 10 S., R. 38 E.
RANGE IN CHARACTERISTICS: These soils are usually moist but are dry in all parts of the control section for 60 to 80 consecutive days within the four-month period following the summer solstice and are moist during the winter months. Thickness of the loess and ash influenced mantle and depth to the contrasting 2Bt horizon is 7 to 13 inches. It has between 0.40 and 1.0 percent acid oxylate Al + 1/2Fe and more than 5 percent volcanic glass and glass aggregate (assumed). The mean annual soil temperature is about 43 to 47 degrees F. Depth to very or extremely gravelly stratified materials ranges from 40 to 60 inches.
The A horizon is ashy loam or ashy silt loam and has hue of 10YR or 7.5YR, value of 3 or 4 moist, 5 or 6 dry and chroma of 2 to 4 moist and dry. It has 0 to 20 percent gravel and 0 to 5 percent cobbles.
The 2Bt horizons have hue of 5YR or 7.5YR, value of 3 or 4 moist, 5 or 6 dry and chroma of 4 moist and dry. It is clay loam or silty clay loam, averaging 27 to 35 percent clay. It has 0 to 20 percent gravel and 0 to 10 percent cobbles.
The 3C horizon is is loam or sandy loam. It has 45 to 70 percent coarse fragments, of which 40 to 50 percent are gravel and 5 to 20 are cobbles.
COMPETING SERIES: These are the Ketchly, Nahahum, Nard, Nardmont, Neuske, and Panak series. The Ketchly soils have an umbric epipedon 10 to 20 inches thick. The Nahahum, Nard, Nardmont, and Neuske soils have E horizons. The Panak soils are dry fro 45 to 60 days following the summer solstice.
GEOGRAPHIC SETTING: McEwen soils are on alluvial terraces. Slopes are 2 to 20 percent. Elevations range from 3,900 to 4,400 feet. The soils formed in mixed alluvium with an influence of loess and volcanic ash in the surface horizons. The climate is characterized by cold and wet winters and hot and dry summers. The mean annual precipitation is 16 to 24 inches. The mean annual temperature is 40 to 45 degrees F. The frost-free is 50 to 90 days. This soil is on the Dolph geomorphic surface.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Crackler, Hankins, Highhorn, Huntrock, Rouen, Stovepipe, Sumpley and Webfoot soils. Crackler and Rouen soils are ashy over loamy-skeletal and are mapped on north slopes of adjacent uplands. Hankins soils have a fine-textured argillic horizon. Highhorn and Huntrock soils are loamy-skeletal, have an ochric epipedon and are mapped on south slopes of adjacent uplands. Stovepipe, Sumpley and Webfoot soils have contrasting textures within the control section and are mapped on adjacent bottom lands.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium. Permeability is moderately slow in the subsoil and moderately rapid in the substratum.
USE AND VEGETATION: These soils are used for timber production, home sites, recreation, hay and pasture and wildlife habitat. The vegetation is mainly ponderosa pine, snowberry, spirea, wax currant, serviceberry, bitterbrush, elk sedge, pinegrass, lupine, heartleaf arnica and wild strawberry.
DISTRIBUTION AND EXTENT: Higher elevation valleys of central and eastern Oregon. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Baker County Area, Oregon, 1942.
REMARKS: This draft reflects a change in classification from fine-loamy, mixed, frigid Vitrandic Haploxeralfs to fine-loamy, isotic, frigid Vitrandic Haploxeralfs.
Diagnostic horizons and features in this pedon include:
Ochric epipedon - from 0 to 5 inches (Oi and A horizon)
Cambic horizon - from 5 to 13 inches (Bw horizon)
Argillic horizon - from 13 to 44 inches (2Bt1, 2Bt2, and 2Bt3 horizons)
Vitrandic feature - upper 13 inches is between 0.4 and 1.0 percent acid oxylate Al + 1/2Fe and more than 5 percent volcanic glass and glass aggregate based on lab data from other soils in the area.