LOCATION OVERLANDTRAIL WY
Tentative Series
Rev. KLS/RJS
04/2016
OVERLANDTRAIL SERIES
The Overlandtrail series consists of very deep, well drained soils that formed in alluvium and/or slope alluvium derived from igneous and metamorphic rock over sedimentary rock. These soils are on hillslopes and eroded fan remnants. Slopes are 1 to 8 percent. Mean annual precipitation is about 300 mm, and mean annual air temperature is about 3.3 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Aridic Haplustalfs
TYPICAL PEDON: Overlandtrail very gravelly sandy loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 7 cm; brown (10YR 5/3) very gravelly sandy loam, dark yellowish brown (10YR 4/4), moist; weak fine granular structure; friable, slightly hard, slightly sticky, slightly plastic; many very fine and fine roots throughout; many fine interstitial pores; 50 percent gravel; finely disseminated calcium carbonate; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (2 to 10 cm thick)
Btky--7 to 34 cm; pale brown (10YR 6/3) loam, yellowish brown (10YR 5/4), moist; weak medium subangular blocky structure; firm, moderately hard, moderately sticky, moderately plastic; many very fine, fine, and medium roots throughout; many fine tubular pores; 5 percent gravel; 5 percent distinct clay films on all faces of peds; 10 percent irregular carbonate masses in matrix; 5 percent irregular gypsum masses in matrix; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (15 to 30 cm thick)
Bky--34 to 90 cm; grayish brown (10YR 5/2) loam, dark yellowish brown (10YR 4/4), moist; weak medium subangular blocky structure; firm, moderately hard, moderately sticky, moderately plastic; many very fine roots throughout; many fine tubular pores; 5 percent gravel; 10 percent irregular carbonate masses in matrix; 15 percent irregular gypsum crystal clusters in matrix; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (25 to 75 cm thick)
2BCky--90 to 150 cm; light olive brown (2.5Y 5/3) very gravelly fine sandy loam, olive brown (2.5Y 4/3), moist; massive; friable, slightly hard, slightly sticky, slightly plastic; few fine roots throughout; many fine tubular pores; 40 percent gravel; 5 percent irregular carbonate coats on rock fragments; 10 percent irregular gypsum crystal clusters in matrix; slightly effervescent; moderately alkaline (pH 8.1).
TYPE LOCATION: Carbon County, Wyoming; USGS Kindt, Wyoming topographic quadrangle; 41 degrees 31 minutes 49.55 seconds north latitude and 107 degrees 5 minutes 3.54 seconds west longitude.
RANGE IN CHARACTERISTICS:
Ochric epipedon thickness - 2 to 10 cm
Depth to argillic horizon - 2 to 10 cm
Depth to secondary carbonates - 2 to 10 cm
Depth to lithologic discontinuity - 50 to 100 cm
A horizon(s)
Hue: 7.5YR or 10YR; dry or moist
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 or 3 dry; 3 or 4 moist
Clay content: 15 to 20 percent
Rock fragments: 15 to 50 percent mixed igneous and metamorphic gravel
Calcium carbonate equivalent: 1 to 5 percent
Reaction: pH 8.0 to 8.4
Btky horizon(s)
Hue: 7.5YR or 10YR; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4; dry or moist
Texture: clay loam, loam
Clay content: 25 to 35 percent
Rock fragments: 2 to 15 percent mixed igneous and metamorphic gravel
Calcium carbonate equivalent: 5 to 15 percent
Gypsum content: 1 to 5 percent
Reaction: pH 8.0 to 8.4
Bky horizon(s)
Hue: 7.5YR to 2.5Y; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 to 4; dry or moist
Texture: sandy clay loam, fine sandy loam, loam
Clay content: 18 to 25 percent
Rock fragments: 2 to 15 percent mixed igneous and metamorphic gravel
Calcium carbonate equivalent: 5 to 15 percent
Gypsum content: 5 to 20 percent
Reaction: pH 7.8 to 8.2
2BCky horizon(s)
Hue: 10YR to 2.5Y; dry or moist
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 to 4; dry or moist
Texture: loam, fine sandy loam, sandy clay loam
Clay content: 12 to 25 percent
Parafragments: 0 to 25 percent paragravel
Rock fragments: 20 to 45 percent shale gravel
Calcium carbonate equivalent: 5 to 15 percent
Gypsum content: 5 to 15 percent
Reaction: pH 7.8 to 8.2
COMPETING SERIES:
Bondoe (MT) - do not have a gypsic horizon
Bonfri (MT) - are moderately deep to a paralithic contact
Chinatown (MT) - are moderately deep to a lithic contact
Fattig (MT) - are moderately deep to a lithic contact
Ferball (MT) - do not have a gypsic horizon
Foreleft (MT) - do not have a gypsic horizon
Raghorn (MT) - do not have secondary carbonate accumulations
Swingstation (MT) - do not have a lithologic discontinuity
GEOGRAPHIC SETTING:
Landform - hillslopes and eroded fan remnants
Elevation - 2,000 to 2,400 meters
Slope - 1 to 8 percent
Parent material - alluvium and/or slope alluvium derived from igneous and metamorphic rock over sedimentary rock
Climate - long, cold winters; cool, moist springs; short, cool summers
Mean annual precipitation - 225 to 300 mm with peak periods of precipitation occurring during the spring
Mean annual air temperature - 3.5 to 5.0 degrees C.
Mean annual soil temperature - 4.5 to 6.0 degrees C.
Frost-free period - 50 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained, moderately slow over moderate permeability, Ksat in the particle-size control section - 1.5 to 5.0 um/sec.
USE AND VEGETATION: Overlandtrail soils are primarily used for rangeland. The potential native vegetation is Wyoming big sagebrush, birdfoot sagebrush, shadscale saltbush, Gardners saltbush, spiny phlox, Sandberg bluegrass, western wheatgrass, bluebunch wheatgrass, and Lettermans needlegrass.
DISTRIBUTION AND EXTENT: Overlandtrail soils are of small extent in southwestern Wyoming. MLRA 34A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Carbon County, Wyoming, 2015. Overlandtrail series is named after the historical Overland Trail stagecoach and wagon trail that dissects the Sage Creek Basin.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 7 cm (A horizon)
Argillic horizon - 7 to 34 cm (Btky horizon)
Secondary carbonates - 7 to 150 cm (Btky, Bky, 2BCky horizons)
Gypsic horizon - 35 to 150 cm (Bky, 2BCky horizons)
Lithologic discontinuity - 90 cm (2BCky horizon)
Particle-size control section - 7 to 34 cm (Btky horizon)
Overlandtrail soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.
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National Cooperative Soil Survey
U.S.A.