LOCATION ST. ANTHONY             ID+WY

Established Series
Rev. RG/ RGK/CBR
05/2018

ST. ANTHONY SERIES

Landscape--plains, alluvial plains, outwash plains, lava fields
Landform--stream terraces, swales of fan remnants
Slope--0 to 12 percent
Parent material--alluvium
Mean annual precipitation--about 375 mm
Mean annual air temperature--about 6.1 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Calcic Pachic Haploxerolls

TYPICAL PEDON: St. Anthony gravelly sandy loam in a cultivated field (Colors are for dry soil unless otherwise noted.)

Ap--0 to 18 cm; brown (10YR 4/3) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure parting to moderate very fine granular; slightly hard, very friable, slightly sticky and slightly plastic; few fine and medium and common very fine roots; many very fine and few fine irregular pores; few pressure faces against gravel; 20 percent gravel; neutral (pH 7.0); abrupt smooth boundary

Bw--18 to 30 cm; brown (10YR 5/3) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure parting to moderate very fine and fine granular; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine and few fine irregular pores; 25 percent gravel; few pressure faces against gravel; neutral (pH 7.0); clear wavy boundary

Bk--30 to 53 cm; brown (10YR 5/3) very gravelly sandy clay loam, dark brown (10YR 3/3) moist; weak fine granular structure; hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular and irregular pores; 50 percent gravel; many pressure faces against gravel; discontinuous calcium carbonate coatings on bottom of rock fragments; strongly effervescent; neutral (pH 7.2); gradual wavy boundary

2Bk--53 to 150 cm; dark gray (10YR 4/1) extremely gravelly coarse sand; single grain; loose; few very fine roots; 70 percent gravel; discontinuous calcium carbonate coatings on bottom of rock fragments; strongly effervescent; neutral (pH 7.2)

TYPE LOCATION: Fremont County, Idaho; latitude 43.94310 degrees north, longitude 111.67966 degrees west, datum WGS 84

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--5.0 to 7.2 degrees C
Thickness of mollic epipedon--50 to 100 cm
Depth to secondary carbonates--20 to 50 cm

Particle-size control section (weighted averages)
Clay content--8 to 18 percent
Total rock fragment content--35 to 65 percent

Ap or A (when present) horizons
Hue--10YR, 7.5YR
Value--4 or 5 dry, 2 or 3 moist
Chroma--2 or 3 dry or moist
Texture (less than 2 mm fraction)--loam, sandy loam
Clay content--10 to 24 percent
Total rock fragment content--5 to 35 percent
Gravel content--15 to 35 percent
Cobble content--0 to 6 percent
Reaction--pH 6.6 to 7.8
Thickness--15 to 36 cm

Bw horizon
Hue--10YR, 7.5YR
Value--4 or 5 dry, 2 or 3 moist
Chroma--2 or 3 dry or moist
Texture (less than 2 mm fraction)--sandy loam, sandy clay loam
Clay content--13 to 28 percent
Total rock fragment content--15 to 75 percent
Gravel content--8 to 50 percent
Cobble content--0 to 10 percent
Reaction--pH 6.6 to 7.8
Thickness--8 to 36 cm

Bk horizon
Hue--10YR, 7.5YR
Value--4 or 5 dry, 2 or 3 moist
Chroma--2 or 3 dry or moist
Clay content--20 to 23 percent
Total rock fragment content--20 to 75 percent
Gravel content--35 to 45 percent
Cobble content--0 to 6 percent
Calcium carbonate equivalent--less than 5 percent
Reaction--pH 6.6 to 7.8
Thickness--0 to 38 cm

2Bk horizon
Value--4 or 5 dry
Chroma--1 to 4 dry
Texture (less than 2-mm fraction)--coarse sand, loamy coarse sand, loamy sand
Clay content--3 to 10 percent
Total rock fragment content--50 to 85 percent
Gravel content--45 to 70 percent
Cobble content--5 to 20 percent
Calcium carbonate equivalent--1 to 10 percent
Reaction--pH 7.9 to 8.0

COMPETING SERIES:
Calpac--calcic horizon; more than 18 percent clay in particle-size control section
Jimsage--no sandy-skeletal discontinuity in lower part of particle-size control section

GEOGRAPHIC SETTING:
Elevation--1370 to 1980 m
Mean annual precipitation--300 to 575 mm
Mean annual air temperature--3.3 to 8.0 degrees C
Frost-free period--50 to 100 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained (subject to irrigation-induced water table)
Saturated hydraulic conductivity (Ksat)--1 to 50 um/sec in upper part of particle-size control section, 150 to 600 um/sec below the discontinuity

USE AND VEGETATION:
Major use--production of irrigated hay, wheat, barley, oats, pasture, and some potatoes
Potential natural vegetation--mountain big sagebrush, bluebunch wheatgrass, Idaho fescue

DISTRIBUTION AND EXTENT: Small extent in southeastern Idaho; MLRAs 13 and 11

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Fremont County, Idaho; 1989

REMARKS:
Diagnostic horizons and other features recognized in this pedon
Mollic epipedon--zone from the surface to a depth of 53 cm (Ap, Bw, and Bk horizons)
Particle-size control section--zone from 25 to 100 cm (part of Bw horizon, Bk horizon, part of 2Bk horizon)

Taxonomic version--Twelfth Edition, 2014

---

National Cooperative Soil Survey
U.S.A.