LOCATION NIGHTHAWK               WA

Established Series
Rev. CDL/RJE/KH
01/2011

NIGHTHAWK SERIES

The Nighthawk series consists of very deep, well drained soils formed in glacial till of mixed mineralogy over calcareous metasediments. These soils are on glaciated foothills and low glaciated mountains. Slopes are 3 to 65 percent. The mean annual precipitation is about 10 inches and the mean annual temperature is about 50 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Calcidic Haploxerolls

TYPICAL PEDON: Nighthawk gravelly loam, range. (Colors are for dry soil unless otherwise noted.)

A1--0 to 4 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; many very fine and fine roots; common very fine and fine tubular pores; 5 percent stones, 5 percent cobbles and 20 percent gravel; neutral (pH 7.0); abrupt smooth boundary. (3 to 5 inches thick)

A2--4 to 8 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak thin platy structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; few very fine and fine tubular pores; 5 percent stones, 5 percent cobbles and 20 percent gravel; neutral (pH 7.2); clear smooth boundary. (3 to 5 inches thick)

AB--8 to 13 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine and common medim roots; few very fine and fine and medium tubular pores; 25 percent gravel and 5 percent cobbles; slightly alkaline (pH 7.4); clear smooth boundary. (4 to 6 inches thick)

Bw--13 to 22 inches; light yellowish brown (10YR 6/4) very gravelly loam, brown (10YR 4/3) moist; massive slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; few very fine, fine and medium tubular pores; 50 percent gravel and 5 percent cobbles; slightly alkaline (pH 7.6); abrupt wavy boundary. (8 to 14 inches thick)

2Ck1--22 to 32 inches; pale yellow (2.5Y 7/4) very gravelly loam, light olive brown (2.5Y 5/4) moist; massive; hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; few very fine, fine and medium tubular pores; 55 percent gravel; thick calcium carbonate coatings on undersides of gravel; strongly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (9 to 11 inches thick)

2Ck2--32 to 60 inches; pale yellow (2.5Y 8/4) very gravelly coarse sandy loam, light yellowish brown (2.5Y 6/4) moist; massive; hard, friable, nonsticky and nonplastic; common very fine and fine and few medium roots; few very fine and fine tubular pores; 55 percent gravel; numerous threads and masses of calcium carbonate; violently effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Okanogan County, Washington; Aeneas Lake Quadrangle; 100 feet east and 5 feet south of the NW corner of the SW1/4 NE1/4 section 13, T.37N., R.26E.; Latitude 48 degrees 42 minutes 32 seconds North and Longitude 119 degrees 30 minutes 12 seconds west; NAD83.

RANGE IN CHARACTERISTICS: The mean annual temperature is 48 to 54 degrees F. The soils are neutral to moderately alkaline. Depth to carbonates is 20 to 30 inches. The mollic epipedon is 10 to 15 inches thick. Rock fragments in the soil range from 5 to 60 percent and average 35 to 50 percent in the particle size control section.

A horizon:
Value: 4 or 5 dry and 2 or 3 moist.

Bw horizon:
Value of 5 or 6 dry and 3 or 4 moist.
Texture: gravelly silt loam, gravelly loam, very gravelly loam or very gravelly silt loam.

2Ck horizon:
Hue: 2.5Y or 10YR
Value: 6 through 8 dry, 5 or 6 moist
Chroma: 2 through 4 moist and dry.
Texture: very gravelly coarse sandy loam, very gravelly loam.

COMPETING SERIES: This is the Peshastin series. Peshastin soils average more than 50 percent rock fragments in the control section.

GEOGRAPHIC SETTING: Nighthawk soils are on glaciated foothills and low mountains. They formed in glacial till of mixed mineralogy over calcareous metasediments. Slopes are 3 to 65 percent. Elevations range from 1,000 to 2,500 feet. These soils occur in a continental climate. The mean annual precipitation is 10 to 12 inches and the mean annual temperature is 48 to 52 degrees F. The frost free season is 140 to 190 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cashmont, Conconully, Newbon, and Vallan soils. Cashmont, Conconully, and Newbon soils have coarse-loamy control sections. Vallan soils have a lithic contact within 20 inches of the surface.

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

USE AND VEGETATION: Irrigated orchards, hay, pasture, and range. Native vegetation is Sandberg bluegrass, dropseed, needlegrass, and threeawn grass.

DISTRIBUTION AND EXTENT: North central Washington. The series is moderately extensive.

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

SERIES ESTABLISHED: Okanagan County, Washington, 1972.

REMARKS: Diagnostic horizons and other features;
Mollic epipedon-the zone from 0 to 13 inches
Cambic horizon-the zone from 13 to 22 inches
Identifiable carbonates- 22 to 60 inches
Aridic soil moisture regime

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National Cooperative Soil Survey
U.S.A.