LOCATION HARKERS UT
Established Series
Rev. LHS/EJ/MEO/JMW/AJE
11/2025
HARKERS SERIES
The Harkers series consists of very deep, well drained soils formed in alluvium and colluvium from mixed sedimentary rocks. The Harkers soils are on alluvial fans and mountain slopes and have slopes of 6 to 50 percent. Mean annual air temperature is about 45 degrees F (7 degrees C) and mean annual precipitation is about 22 inches (570 mm)
TAXONOMIC CLASS: Fine, smectitic, frigid Typic Palexerolls
TYPICAL PEDON: Harkers loam - native rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 14 inches (0 to 36 cm); very dark grayish brown (10YR 3/2) loam, very dark brown (10YR 2/2) moist; moderate medium granular structure that parts to fine granular structure; slightly hard, friable, moderately sticky, moderately plastic; common coarse medium, fine and very fine roots; common very fine and few fine pores; 15 percent gravel; neutral (pH 7.0); clear smooth boundary. (10 to 17 inches (25 to 43 cm) thick)
BA--14 to 19 inches (36 to 48 cm); grayish brown (10YR 5/2) gravelly clay loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; hard, firm, moderately sticky, moderately plastic; common coarse, medium, fine and very fine roots; few very fine pores; 25 percent gravel; neutral (pH 7.0); clear smooth boundary. (0 to 8 inches (0 to 20 cm) thick)
Bt1--19 to 42 inches (48 to 107 cm); brown (7.5YR 5/4) gravelly clay, dark reddish brown (5YR 3/4) moist ped; brown (7.5YR 4/3) moist; strong medium prismatic structure that parts to strong medium blocky structure; very hard, extremely firm, very sticky, very plastic; few coarse, medium, fine and very fine roots; few very fine pores; clay films are moderately thick continuous on faces of peds; 30 percent gravel; neutral (pH 7.2); gradual wavy boundary. (15 to 24 inches 38 to 61 cm) thick)
Bt2--42 to 58 inches (107 to 147 cm); brown (7.5YR 5/4) very gravelly clay, dark reddish brown (5YR 3/4) moist ped, brown (7.5YR 4/3) crushed moist; strong medium prismatic structure that parts to strong medium blocky structure; very hard, extremely firm, very sticky, very plastic; few fine and very fine roots; few very fine pores; clay films are moderately thick continuous on faces of peds; 55 percent gravel; neutral (pH 7.0); clear smooth boundary. (12 to 24 inches (30 to 61 cm) thick)
Bk--58 to 80 inches (147 to 203 cm); light yellowish brown (10YR 6/4) very gravelly clay loam, brown (7.5YR 5/4) moist; massive; hard, very firm, very sticky; few fine and very fine roots; few fine pores; 60 percent gravel; slightly calcareous; neutral (pH 7.0).
TYPE LOCATION: Salt Lake County, Utah; about 4.5 miles west of Bingham-Magna highway along KCPX T. V. tower road and 500 feet west up the slope from this road; near the center of sec. 36, T.2S., R.3W.
RANGE IN CHARACTERISTICS: Harkers soils have very dark grayish brown, neutral, loam A horizons, and brown, neutral, gravelly clay Bt horizons over very gravelly clay loam Bk horizons. The solum ranges in thickness from 40 inches (100 cm) to more than 5 feet (150 cm). The mollic epipedon ranges from 10 to 20 inches (25 to 50 cm) thick. The mean annual soil temperature is about 43 to 47 degrees F (6 to 8 degrees C) and the mean summer temperature at 20 inches (50 cm) is about 59 to 65 F (15 to 18 degrees C). The soils are usually moist but are dry for more than 60 consecutive days in all parts of the soil between 4 and 12 inches (10 to 30 cm) in more than 7 out of 10 years.
Harkers soils have very dark grayish brown, neutral, loam A horizons, and brown, neutral, gravelly clay Bt horizons over very gravelly clay loam Bk horizons.
The A horizon has hue of 10YR or 7.5YR, value of 3 through 5 dry, 2 or 3 moist, and chroma of 2 or 3. The upper portion of the A horizon has moderate to strong, medium to fine granular structure or moderate medium, thin platy structure and the lower portion of the A horizon ranges from weak medium to fine subangular blocky structure.
The Bt horizon(s) has hue of 7.5YR, 5YR or 2.5YR, value of 5 through 7 dry, 3 through 5 moist, and chroma of 2 through 4. It is gravelly heavy clay loam to gravelly clay with 20 to 35 percent cobble and gravel. This horizon has moderate to strong prismatic parting to angular blocky structure. Splotches of lime may occur in pockets of disintegrating rocks at depths of below 36 inches (91 cm) in the Bt horizon. The horizon is neutral or slightly acid and the matrix is noncalcareous. A weak lime horizon occurs at depths of 5 feet or more in some pedons. The Bt horizon extends to depths of 48 inches (122 cm) or more. The Bk horizons are cobbly, very cobbly or very gravelly clay loams containing less clay than the Bt horizon.
COMPETING SERIES: These are the
Bridgecreek,
Coser,
Deer Creek,
Eoj,
Goodington,
Lynnbow,
Mohocken,
Norcan,
Rands, and
Spikebutte series. Bridgecreek, Coser, Mohocken, and Spikebutte soils have a paralithic contact between 50 and 100 cm. Deer Creek soils have 30 to 65 percent lime in the Bk horizon and a calcic horizon. Eoj soils are slightly to moderately alkaline throughout. Goodington soils have a lithic contact between 100 and 150 cm. Lynnbow soils have a paralithic contact between 100 and 150 cm. Norcan soils have less than 10 percent rock fragments throughout. Rands soils have less than 5 percent gravel throughout.
SETTING: Harkers soils are on short to long sloping alluvial fans to very steep mountain slopes at elevations between 5,500 and 7,500 feet (1665 to 2270 m). Slope gradients are 6 to 50 percent. The soils formed in alluvium and colluvium from mixed sedimentary rocks. The climate is moist subhumid. The mean annual temperature is 40 to 45 degrees F (4 to 7 degrees C). The mean summer temperature is about 64 degrees F (18 degrees C). Average annual precipitation is 20 to 25 inches (510 to 635 mm) coming mostly as snow. The frost-free period is less than 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Copperton,
Deer Creek,
Dry Creek,
Gappmayer,
Henefer,
Horrocks,
Wallsburg, and
Yeates Hollow soils. Copperton soils lack B horizons, have mean annual soil temperatures more than 47 degrees F (8 degrees C) and have lime accumulations within 40 inches (100 cm). Deer Creek soils have a calcic horizon within depths of 40 inches (100 cm). Dry Creek soils have mean annual soil temperature of more than 47 degrees F (8 degrees C) and have calcic horizons within depths of 40 inches (100 cm). Gappmayer soils have albic horizons. Henefer soils have mollic epipedons more than 20 inches (50 cm) thick. Horrocks soils have more than 35 percent coarse fragments and less than 35 percent clay in the argillic horizon. Wallsburg soils are less than 20 inches (50 cm) deep over bedrock. Yeates Hollow soils have more than 35 percent coarse fragments and a lithic contact between 40 to 60 inches (100 and 150 cm).
DRAINAGE AND PERMEABILITY: Well-drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: Used for spring and fall range, wildlife, and watershed. Vegetation is mainly oakbrush, black sagebrush, big sagebrush, mulesear dock, yellowbrush, and cheatgrass.
DISTRIBUTION AND EXTENT: Central and northern Utah, Wasatch Mountains. MLRA 47. Harkers series is moderately extensive.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Sanpete Area, Utah, 1971.
REMARKS: Harkers soils were formerly classified as Brunizems.
OSED scanned by NSSQA. Last reviewed by state 9/71.
Added metric depths and updated competing series and geographically associated soils 11/2025. -JBB
National Cooperative Soil Survey
U.S.A.