LOCATION OMAHALING OREstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Fluvaquentic Haploxerolls
TYPICAL PEDON: Omahaling fine sandy loam - on a level flood plain. (When described (05/19/86), soil was moist throughout. Colors are for moist soil unless otherwise noted.)
Ap--0 to 4 inches; very dark brown (10YR 2/2) fine sandy loam, dark grayish brown (10YR 4/2) dry; moderate very fine granular structure; slightly hard, friable, nonsticky and nonplastic; common very fine roots; common very fine irregular pores; mildly alkaline (pH 7.4); abrupt wavy boundary. (0 to 12 inches thick)
AC--4 to 19 inches; very dark brown (10YR 2/2) fine sandy loam, dark grayish brown (10YR 4/2) dry; massive; slightly hard, friable, nonsticky and nonplastic; few very fine, fine, and medium roots; many very fine irregular pores; 5 percent rounded gravel; mildly alkaline (pH 7.4); abrupt wavy boundary. (10 to 18 inches thick)
2C1--19 to 23 inches; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; common fine distinct dark yellowish brown mottles; weak fine platy structure; slightly hard, friable, nonsticky and nonplastic; few very fine roots; common very fine tubular pores; mildly alkaline (pH 7.6); abrupt wavy boundary. (0 to 4 inches thick)
2C2--23 to 29 inches; very dark brown (10YR 2/2) gravelly sand, dark gray (10YR 4/1) dry; common medium distinct dark yellowish brown mottles; single grain; loose, nonsticky and nonplastic; few very fine roots; few very fine irregular pores; 20 percent subrounded gravel; 5 percent iron-cemented lenses (1-2 centimeters thick); mildly alkaline (pH 7.6); abrupt wavy boundary. (0 to 8 inches thick)
2C3--29 to 48 inches; very dark brown (10YR 2/2) silt loam with lenses of very fine sandy loam throughout, dark grayish brown (10YR 4/2) dry; common fine distinct dark yellowish brown mottles usually adjacent to roots and lining pores; massive; slightly hard, friable, sticky and nonplastic; few medium roots; few fine irregular pores; mildly alkaline (pH 7.6); abrupt wavy boundary. (7 to 20 inches thick)
3C4--48 to 60 inches; very dark brown (10YR 2/2) extremely gravelly coarse sand, dark gray (10YR 4/1) dry; single grain; loose, nonsticky and nonplastic; 80 percent rounded gravel and 5 percent rounded cobbles; mildly alkaline (pH 7.8).
TYPE LOCATION: Deschutes County, Oregon; 400 feet south and 100 feet west of the northeast corner of the southwest quarter of section 26, T. 14 S., R. 10 E. (Latitude 44 degrees, 19 minutes, 28 seconds N, Longitude 121 degrees, 30 minutes, 12 seconds W)
RANGE IN CHARACTERISTICS: These soils are usually moist but are dry in all parts of the soil moisture control section for 45 to 60 consecutive days after the summer solstice. The mean annual soil temperature is 44 to 47 degrees F. Depth to bedrock is 60 inches or more. The mollic epipedon is 15 to 20 inches thick. Depth to mottling with chroma of 2 or less is 15 to 30 inches. Below the mollic epipedon organic matter decreases irregular with depth. The particle-size control section averages 30 to 60 percent sand and 5 to 15 percent clay.
The A horizon has hue of 10YR, value of 2 moist, 4 dry and chroma of 2 moist and dry. It contains 0 to 10 percent rounded gravel. It is neutral or mildly alkaline.
The 2C horizon has hue of 10YR, value of 2 or 3 moist, 4 or 5 dry and chroma of 2 moist and 1 or 2 dry. It contains 0 to 25 percent gravel. It has common distinct or prominent mottles. It is silt loam, very fine sandy loam, or loam with strata of sand. It is neutral or mildly alkaline.
The 3C horizon has hue of 10YR, value of 2 or 3 moist, 4 dry and chroma of 2 or 3 moist, 1 or 2 dry. It contains 60 to 80 percent gravel, 5 to 15 percent cobbles and 65 to 95 percent total coarse fragments.
COMPETING SERIES: These are the Cubcreek and Kegel series. Cubcreek soils are moderately well drained and are dry for 60 to 75 consecutive days. Kegel soils have mean annual precipitation of 20 to 35 inches, have a mixed conifer overstory, and have an O horizon.
GEOGRAPHIC SETTING: The Omahaling soils are on flood plains at elevations of 2800 to 4000 feet. Slopes are 0 to 5 percent. The soils formed in mixed ash and alluvium. The climate is characterized by cold, wet winters and hot, dry summers. The mean annual precipitation is 12 to 18 inches, falling mostly as snow. The mean annual temperature is 42 to 47 degrees F. The frost-free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ermabell soils. Ermabell soils are on adjacent stream terraces and are well drained.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderate permeability. A water table is at 24 and 36 inches from April to June. Flooding is rare.
USE AND VEGETATION: These soils are used for hay, pasture, wildlife habitat, recreation, and homesites. Potential native vegetation is willow, quaking aspen, and sedges.
DISTRIBUTION AND EXTENT: Deschutes Basin of central Oregon; MLRA 6. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Deschutes County (Upper Deschutes River Area), Oregon, 1992.
REMARKS: Diagnostic horizons and features in the pedon are:
Xeric soil moisture regime.
mollic epipedon - from the soil surface to 19 inches. (Ap and AC horizons)
Fluvaquentic - There is an irregular decrease in organic matter with depth, mottles with chroma of 2 or less are present at 19 to 48 inches, and the soil is saturated at 24 to 36 inches for about 90 days.