LOCATION REDGAP WY
Tentative Series
ALB-DPG-DEW
04/2025
REDGAP SERIES
Depth class: Deep and Very deep
Drainage class: Well drained
Saturated hydraulic conductivity class: Moderately high
Parent material: Slope alluvium, colluvium, alluvium, or eolian sands over residuum weathered from interbedded sedimentary rocks or sandstone
Geomorphic location: Hillslopes, alluvial fans, dune fields, inset fans, alluvial flats, or fan remnants
Slope range: 0 to 20 percent
Mean annual temperature: 4.5 degrees C (40 degrees F)
Mean annual precipitation: 205 millimeters (8 inches)
TAXONOMIC CLASS:
Coarse-loamy, mixed, superactive, frigid Sodic Ustic Haplocambids
TYPICAL PEDON: Redgap loam in rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 8 centimeters; pale brown (10YR 6/3) loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; soft, very friable, nonsticky, nonplastic; many very fine and fine roots throughout; many very fine and fine interstitial pores; slightly effervescent; moderately alkaline (pH 8.4); clear smooth boundary.
Bk--8 to 23 centimeters; pale brown (10YR 6/3) fine sandy loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; common very fine and many fine roots throughout; common very fine and many fine interstitial pores; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary.
Bkn--23 to 41 centimeters; yellowish brown (10YR 5/4) fine sandy loam, brown (10YR 4/3) moist; strong fine subangular blocky structure; hard, very firm, nonsticky, nonplastic; common fine roots throughout; common fine interstitial pores; strongly effervescent; strongly alkaline (pH 9.0); clear smooth boundary.
BCkn--41 to 65 centimeters; dark yellowish brown (10YR 4/4) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; moderately hard, firm, nonsticky, nonplastic; common very fine and fine roots throughout; common very fine and fine interstitial pores; slightly effervescent; strongly alkaline (pH 9.0); clear smooth boundary.
C1--65 to 90 centimeters; brown (10YR 4/3) loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable, slightly sticky, slightly plastic; common fine roots throughout; common fine interstitial pores; slightly effervescent; strongly alkaline (pH 8.8); clear smooth boundary.
C2--90 to 130 centimeters; yellowish brown (10YR 5/4) fine sandy loam, brown (10YR 5/3) moist; massive; slightly hard, friable, nonsticky, nonplastic; very slightly effervescent; strongly alkaline (pH 9.0); clear smooth boundary.
C3--130 to 200 centimeters; dark yellowish brown (10YR 4/4) fine sandy loam, brown (10YR 4/3) moist; massive; slightly hard, friable, nonsticky, nonplastic; slightly effervescent; strongly alkaline (pH 8.8).
TYPE LOCATION:
Sweetwater County, WY
USGS Quadrangle: Wilkins Peak
Latitude: 41.4039000
Longitude: -109.2507200
Datum: WGS84
Coordinates source: Hand-held GPS
RANGE IN CHARACTERISTICS:
Depth to cambic horizon: 4 to 10 centimeters
Depth to sodic properties: 0 to 40 centimeters
Depth to bedrock: 109 to 200 centimeters
Particle-size control section (weighted averages):
Clay content-8 to 17 percent
Sand content-54 to 79 percent
Total rock fragments-0 to 28 percent
(Individual horizons allow for textures with greater than 18 percent clay but are outside the control section or thin enough that the weighted average clay in the control section is always under 18 percent. Some horizons may have a high calcium carbonate equivalent and/or some secondary calcium carbonate accumulation, but the profile should never meet the full requirements for a calcic diagnostic horizon.)
A horizon:
Hue-10YR or 2.5Y
Value-5 to 7 dry; 3 to 5 moist
Chroma-2 to 4
Texture (less than 2 mm fraction)-Fine sandy loam, sandy loam, loamy fine sand, or loam
Clay content-4 to 18 percent
Rock fragments-0 to 50 percent; 0 to 50 percent channers, 0 to 25 percent gravels, 0 to 2 percent cobbles
Calcium carbonate equivalent-0 to 15 percent
Sodium absorption ratio-0 to 25
Reaction-pH 6.8 to 9.4
Thickness-4 to 13 centimeters
Bk/Bw/BCk horizon (s) (when present):
Hue-7.5YR to 2.5Y
Value-5 to 8 dry; 3 to 5 moist
Chroma-3 or 4 dry; 3 to 6 moist
Texture (less than 2 mm fraction)-Fine sandy loam, sandy loam, loamy fine sand, or loam
Clay content-5 to 18 percent
Rock fragments-0 to 40 percent; 0 to 40 percent channers, 0 to 5 percent gravels, 0 to 2 percent cobbles
Calcium carbonate equivalent-0 to 15 percent
Sodium absorption ratio-0 to 3 percent
Reaction-pH 7.2 to 8.4
Thickness-0 to 96 centimeters
Bkn/Bknz/BCkn horizon (s):
Hue-10YR or 2.5Y
Value-4 to 7 dry; 2 to 6 moist
Chroma-3 or 4 dry; 3 to 6 moist
Texture (less than 2 mm fraction)-Fine sandy loam, sandy loam, very fine sandy loam, loam, loamy sand, or loamy fine sand
Clay content-5 to 18 percent
Rock fragments-0 to 50 percent; 0 to 50 percent channers, 0 to 30 percent gravels
Calcium carbonate equivalent-2 to 15 percent
Sodium absorption ratio-13 to 30 percent
Electrical conductivity-0 to 19 dS/m
Reaction-pH 8.6 to 9.8
Thickness-25 to 168 centimeters
C horizon (s) (when present):
Hue-10YR or 2.5Y
Value-4 to 8 dry; 4 to 6 moist
Chroma-2 to 8
Texture (less than 2 mm fraction)-Fine sandy loam, sandy loam, loamy fine sand, loamy sand, or loam
Clay content-5 to 18 percent
Rock fragments-0 to 50 percent; 0 to 25 percent gravels; 0 to 50 percent channers, 0 to 8 percent parachanners
Calcium carbonate equivalent-0 to 25 percent
Sodium absorption ratio-0 to 25 percent
Reaction-pH 7.2 to 9.8
Thickness-0 to 172 centimeters
COMPETING SERIES:
Firehole (WY) - has sodic properties below 40 centimeters from the mineral soil surface
GEOGRAPHIC SETTING:
Parent material: Slope alluvium, colluvium, alluvium, or eolian sands, over residuum weathered from interbedded sedimentary rocks or sandstone
Landform: Hillslopes, alluvial fans, dune fields, inset fans, alluvial flats, or fan remnants
Slope: 0 to 20 percent
Mean annual temperature range: 2.5 to 7.0 degrees C (37 to 45 degrees F)
Mean annual precipitation range: 180 to 230 millimeters (7 to 9 inches)
Frost-free period: 50 to 100 days
Elevation: 1,840 to 2,350 meters (6,040 to 7,710 feet)
Climate: Long, cold winters; cool, moist springs; short, warm summers
GEOGRAPHICALLY ASSOCIATED SOILS:
None listed.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: Well drained
Saturated Hydraulic Conductivity: 1.5 to 5 m/sec
USE AND VEGETATION:
Redgap soils are primarily used for rangeland. The potential native vegetation is Indian ricegrass, Sandberg bluegrass, bottlebrush squirreltail, thickspike wheatgrass, needle and thread, Wyoming big sagebrush, Gardener's saltbush, bud sagebrush, and greasewood.
DISTRIBUTION AND EXTENT:
Redgap soils are of moderate extent in southwestern Wyoming; MLRA 34A.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED:
Sweetwater County, WY 2023. Redgap series is a coined phrase.
REMARKS:
Typical Pedon Taxonomic Features:
Ochric epipedon-0 to 8 centimeters (A horizon)
Cambic horizon-8 to 41 centimeters (Bk and Bkn horizons)
Sodic properties-23 to 200 centimeters (Bkn, BCkn, C1, C2 and C3 horizons)
Particle-size control section-25 to 100 centimeters
Taxonomic Version: Keys to Soil Taxonomy, 13th edition, (2022)
National Cooperative Soil Survey
U.S.A.