LOCATION HELLGATE WAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Ultic Haploxerolls
TYPICAL PEDON: Hellgate gravelly coarse sandy loam - on a west facing 14 percent slope, at 2,100 feet elevation, under a ponderosa pine canopy. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 3 inches; partially decomposed organic material from needles, leaves, grass, and twigs; abrupt smooth boundary.
A--3 to 11 inches; grayish brown (10YR 5/2) gravelly coarse sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, common fine, and few medium roots; 25 percent fine pebbles; neutral (pH 6.8); abrupt wavy boundary. (8 to 18 inches thick)
AB--11 to 15 inches; brown (10YR 5/3) gravelly coarse sandy loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, and medium roots; 20 percent fine pebbles; neutral (pH 7.0); clear wavy boundary. (0 to 8 inches thick)
Bw--15 to 28 inches; very pale brown (10YR 7/3) gravelly coarse sandy loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, medium, and few coarse roots; 15 percent fine pebbles, and percent coarse pebbles; neutral (pH 7.2); abrupt smooth boundary. (6 to 28 inches thick)
C1--28 to 39 inches; pale brown (10YR 6/3) very gravelly loamy coarse sand, brown (10YR 4/3) moist; massive; soft; very friable; nonsticky and nonplastic; few fine and medium roots; 25 percent fine pebbles; 15 percent coarse pebbles, and 5 percent cobbles; slightly alkaline (pH 7.4); gradual wavy boundary. (10 to 24 inches thick)
C2--39 to 60 inches; multicolored very gravelly coarse sand; single grain; loose, nonsticky and nonplastic; 30 per;cent coarse pebbles, and 10 percent fine pebbles; neutral (pH 7.2).
TYPE LOCATION: Colville Indian Reservation; Ferry County, Washington; about 8 miles south-southwest of the town of Keller; 800 feet south and 1,750 feet east of the northwest corner of sec. l, T. 28 N., R. 32 E., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches ranges from 47 to 50 degrees F. These soils are usually moist but are dry in all parts of the moisture control section for 75 to 90 consecutive days following the summer solstice. The mollic epipedon is 8 to 18 inches thick. Solum thickness is 22 to 36 inches. The particle-size control section averages 5 to 12 percent clay, 25 to 50 percent coarse and very coarse sand, and 15 to 35 percent rock fragments.
The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3 dry or moist. It is gravelly loam or gravelly coarse sandy loam. It has weak fine or medium subangular blocky structure. This horizon is 15 to 30 percent mostly fine pebbles. Reaction is slightly acid or neutral.
The AB horizon is absent in some pedons.
The Bw horizon has value of 5 through 7 dry, 3 through 5 moist, and chroma of 3 or 4 dry or moist. It is loam, sandy loam, or coarse sandy loam and is nongravelly in some pedons. It has weak fine or medium subangular blocky structure. This horizon is 10 to 30 pebbles and 0 to 5 percent cobbles. Reaction is slightly acid or neutral.
The C horizon is multicolored or has hue of 10YR or 2.5Y, value of 6 or 7 dry, 4 or 5 moist, and chroma of 3 or 4 dry or moist. It is coarse sandy loam, loamy coarse sand, or coarse sand, and is gravelly or very gravelly. It is 20 to 45 percent pebbles and 0 to 5 percent cobbles. Reaction is neutral or slightly alkaline.
COMPETING SERIES: These are the Ardening, Billyridge, Burrant, Canderly, Catelli, Crouch, Ginnis, Picard, Rebecca, Roney, Shangland, Texascreek, and Wind River soils. Ardening soils have 15 to 35 percent weathered schist fragments in the particle-size control section and are dry for 60 to 75 consecutive days. Billyridge soils are dry for 60 to 75 consecutive days. Burrant soils have 0 to 5 percent rock fragments in the particle-size control section. Canderly soils have a mean annual soil temperature of 54 to 56 degrees F and have a solum more than 40 inches deep. Catelli, Ginnis, Shangland, and Texascreek soils have a paralithic contact at 20 to 40 inches. Crouch soils have a mean annual soil temperature of 56 to 58 degrees F. Picard and Rebecca soils are dry for 90 to 105 consecutive days. Roney soils have a lithic contact at 20 to 40 inches. Wind River soils have a mean soil temperature of 50 to 54 degrees F and have a solum 15 to 25 inches thick.
GEOGRAPHIC SETTING: Hellgate soils are on fan terraces and toeslopes of mountains. These soils formed in colluvium residuum, and valley fill from highly weathered granitic rocks with a minor component of loess and volcanic ash. Slopes are 3 to 20 percent. Elevations range from 1,600 to 2,700 feet. The climate is characterized by warm, dry summers and cold, moist winters. The average annual precipitation is 15 to 18 inches. The mean January temperature is about 25 degrees F, the mean July temperature is about 67 degrees F, and the mean annual air temperature is about 47 degrees F. The frost-free period is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bearspring, Dinkelman, Georgecreek, Skanid, Swakane, Vanbrunt, and Whitestone soils. Bearspring and Dinkelman soils are frigid. Georgecreek soils are fine-loamy. Skanid and Swakane soils are less than 20 inches to a paralithic or lithic contact, respectively. Vanbrunt soils are 20 to 40 inches to a lithic contact. Whitestone soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; permeability is moderately rapid.
USE AND VEGETATION: Timber production, grazing, wildlife habitat, and watershed are the principal uses. Native vegetation is ponderosa pine and scattered Douglas-fir with an understory of Idaho fescue, bluebunch wheatgrass, antelope bitterbrush, Saskatoon serviceberry, arrowleaf balsamroot, common yarrow, prairie lupine, and ballhead sandwort.
DISTRIBUTION AND EXTENT: Northcentral Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Colville Indian Reservation; Ferry County, Washington, 1987.
REMARKS: Diagnostic horizons and features recognized in this soil are a mollic epipedon from 3 to 15 inches and a cambic horizon from 15 to 28 inches. The particle-size control section averages 30 percent rock fragments.