LOCATION CRANEGULCH IDEstablished Series
The Cranegulch series consists of very deep, well drained soils with slow permeability that formed in loamy alluvium and colluvium from fine pyroclastic and granitic sediments. Slopes range from 2 to 50 percent in foothills. The average annual precipitation is about 15 inches and the average annual temperature is about 50 degrees F.
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Argixerolls
TYPICAL PEDON: Cranegulch loam -- on a 22 percent slightly convex southeast-facing slope at 3,400 feet elevation in rangeland. When described on September 20, 1995, the soil was dry to 32 inches and slightly moist below. (Colors are for air-dry soil unless otherwise noted.)
A1--0 to 3 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak medium platy structure parting to moderate fine and medium granular; soft, very friable lightly sticky and slightly plastic; common very fine and fine, few medium roots; many very fine and fine, few medium tubular pores; 5 percent gravel; neutral (pH 7.0); clear smooth boundary. (2 to 10 inches thick)
A2--3 to 10 inches; grayish brown (10YR 5/2) loam, very dark brown (10YR 2/2) moist; moderate medium platy structure parting to moderate fine and medium granular; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium roots; many very fine and fine, few medium tubular pores; 5 percent gravel; neutral (pH 6.8); diffuse wavy boundary. (2 to 10 inches thick)
Bt1--10 to 14 inches; yellowish brown (10YR 5/4) sandy clay loam, dark yellowish brown (10YR 3/4) moist; pockets of A material, grayish brown (10YR 5/2), dark brown (10YR 3/3) moist; weak fine subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; few very fine, fine and medium roots; common very fine and fine tubular pores; few distinct clay films on faces of peds, in pores and bridging sand grains; few bleached silt grains on faces of peds; 10 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (1 to 4 inches thick)
Bt2--14 to 21 inches; yellowish brown (10YR 5/4) sandy clay, dark yellowish brown (10YR 3/4) moist; moderate medium and coarse subangular blocky structure; very hard, friable, very sticky and moderately plastic; few very fine and fine roots; common very fine and fine tubular pores; common distinct clay films on faces of peds, in pores and bridging sand grains; 10 percent gravel; neutral (pH 7.1); clear smooth boundary. (5 to 12 inches thick)
Bt3--21 to 33 inches; yellowish brown (10YR 5/4) clay, dark yellowish brown (10YR 3/4) moist; moderate fine and medium prismatic structure; very hard, firm, very sticky and moderately plastic; few very fine and fine roots; few very fine and fine tubular pores; many prominent clay films on faces of peds, in pores and bridging sand grains; roots are matted on vertical and horizontal faces of peds; very dark brown 10YR 2/2 organic stains on vertical and horizontal faces of peds; 10 percent gravel; neutral (pH 7.0); gradual wavy boundary. (8 to 14 inches thick)
Bt4--33 to 50 inches; light yellowish brown (10YR 6/4) sandy clay, dark yellowish brown (10YR 4/4) moist; moderate medium prismatic structure parting to strong medium and coarse subangular blocky; very hard, firm, very sticky and moderately plastic; few very fine and fine roots; few very fine and fine tubular pores; common prominent clay films on faces of peds, in pores and bridging sand grains; roots are matted on vertical and horizontal faces of peds; 10 percent gravel; neutral (pH 6.8); gradual wavy boundary. (10 to 21 inches thick)
Bt5--50 to 60 inches; light yellowish brown (10YR 6/4) clay loam, dark yellowish brown (10YR 4/4) moist; strong medium and coarse subangular blocky structure; very hard, firm, very sticky and very plastic; few very fine and fine roots; common very fine and fine tubular pores; common distinct clay films on faces of peds, in pores and bridging sand grains; continuous lamellae, yellowish brown (10YR 5/4) sandy clay, dark yellowish brown (10YR 3/4) moist, 2 to 10 mm thick and 1 to 4 inches apart; 10 percent gravel; neutral (pH 6.9).
TYPE LOCATION: Ada County, Idaho; about 3.5 miles north and 1.25 mile west of Camels Back Park in Boise; 1,350 feet west and 1,550 feet south of the northeast corner of section 16, T.4 N., R.2 E.; USGS Boise North Quadrangle; Latitude - 43 degrees, 41 minutes, 13 seconds N. and Longitude - 116 degrees, 13 minutes, 06 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 10 to 20 inches
Depth to bedrock - 60 inches or more
Reaction - neutral or slightly acid
Particle-size control section - 35 to 45 clay; 0 to 35 rock fragments; and 15 to 25 percent medium and coarser sand
Moisture control section - dry 60 to 90 consecutive days following the summer solstice
Average annual soil temperature - 49 to 53 degrees F.
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Clay content - 15 to 20 percent
Rock fragments - 0 to 10 percent cobbles, 0 to 25 percent gravel and 0 to 35 percent total
Bt1 horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Texture - SCL or CL
Clay content - 20 to 30 percent
Rock fragments - 0 to 10 percent cobbles, 0 to 25 percent gravel and 0 to 35 percent total
Bt2 through Bt5 horizons
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Texture - SC, C or CL
Clay content - 35 to 50 percent
Rock fragments - 0 to 10 percent cobbles, 0 to 25 percent gravel and 0 to 35 percent total
COMPETING SERIES: These are the Daphnedale, Keating, Maple Hollow, Midvale, Ramo, Roacha and Widmer (T) series. Daphnedale, Roacha and Widmer soils are 20 to 40 inches deep to a paralithic contact. Keating soils are 20 to 40 inches deep to a lithic contact. Maple Hollow soils have a calcic horizon. Midvale soils have silica cementation in the upper 40 inches. Ramo soils have buried argillic horizons and lithologic discontinuities.
GEOGRAPHIC SETTING: Cranegulch soils are on all hillslope positions and on structural benches and landslide deposits at elevations of 2,700 to 4,100 feet. Slopes range from 2 to 50 percent. These soils formed in loamy alluvium and colluvium from fine pyroclastic and granitic sediments deposited as basin-margin subaqueous deltas. The average annual precipitation is 13 to 17 inches. The average annual temperature is 47 to 51 degrees F. The frost-free period is 110 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ada, Adelmann, Hullsgulch, Piercepark and Quailridge soils. Ada and Adelmann soils are clayey-skeletal and occur on similar geomorphic positions. Hullsgulch and Quailridge soils are fine-loamy, have an aridic bordering xeric soil moisture regime and occur on more convex and exposed geomorphic positions. Piercepark soils have mollic epipedons 20 to 30 inches thick, are fine-loamy, have an aridic bordering xeric soil moisture regime and occur on footslope and toeslope positions.
DRAINAGE AND PERMEABILITY: Well drained; slow to very rapid runoff; slow permeability.
USE AND VEGETATION: Cranegulch soils are used mainly for rangeland. Native vegetation is xeric big sagebrush and bluebunch wheatgrass. Some areas are used for homesites.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 10. Cranegulch soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Boise County Area, Idaho, Parts of Ada and Boise Counties, 2005.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon - zone from the soil surface to 10 inches (A1 and A2 horizons)
Argillic horizon - zone from 14 to 60 inches (Bt1, Bt2, Bt3, Bt4 and Bt5 horizons)
Particle-size control section - zone from 14 to 34 inches
Linear extensibility - 4.0 to 6.0 cm (assumed) from 0 to 40 inches.
Soil moisture regime xeric