LOCATION LASCHANCE ID
Established Series
IRD: FRK/CBR
10/2026
LASCHANCE SERIES
The Laschance series consists of shallow, well drained soils formed in colluvium over residuum weathered from dolomite, limestone, and calcareous sandstone. These soils are on mountain slopes and hill slopes. Slopes range from 10 to 70 percent. The mean annual precipitation is about 510 mm, and mean annual air temperature is about 4.4 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Lithic Haploxerolls
TYPICAL PEDON: Laschance gravelly loam in rangeland. (colors are for dry soil unless otherwise noted).
A--0 to 22 cm; very dark grayish brown (10YR 3/2) gravelly loam, very dark brown (10YR 2/2) moist; weak very fine and fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots; common very fine and fine irregular pores; 5 percent fine and 25 percent medium gravel; neutral (pH 7.2); clear wavy boundary.
Bk1--22 to 28 cm; brown (10YR 4/3) very gravelly loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine and common fine and medium roots; common very fine and fine irregular pores; very slightly effervescent; common fine and medium secondary calcium carbonate coats on the bottoms of rock fragments; 5 percent fine gravel, 30 percent medium and coarse gravel, and 5 percent cobbles; neutral (pH 7.2); abrupt irregular boundary.
Bk2--28 to 39 cm; brown (10YR 5/3) extremely cobbly loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; common very fine and fine irregular pores; slightly effervescent; common fine and medium secondary calcium carbonate coats around rock fragments; 30 percent medium and coarse gravel, 50 percent cobbles, and 5 percent stones; slightly alkaline (pH 7.6); abrupt wavy boundary.
R--39 cm; dolomite bedrock.
TYPE LOCATION: Caribou County, Idaho; Alexander, USGS topographic quadrangle; latitude 42.6669972, longitude -111.7186361, WGS84 Datum
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--3.3 to 7.0 degrees C.
Mean summer soil temperature--15.0 to 18.3 degrees C.
Thickness of mollic epipedon--18 to 40 cm
Depth to bedrock--25 to 50 cm
Particle-size control section (weighted averages)
Clay content--7 to 14 percent
Total rock fragments--40 to 80percent
Calcium carbonate equivalent--1 to 6 percent
A horizon
Value--3 to 5 dry; 2 or 3 moist
Chroma--2 or 3 dry or moist
Texture (less than 2 mm fraction)--loam, sandy loam
Clay content--5 to 19 percent
Rock fragments--15 to 35 percent - 15 to 35 percent gravel, 0 to 5 percent cobbles, 0 to 5 percent stones
Reaction--6.6 to 7.6
Thickness--7 to 22 cm
Bk1 horizon
Value--4 or 5 dry; 2 or 3 moist
Chroma--2 or 3 dry or moist
Texture (less than 2 mm fraction)--loam, fine sandy loam, or sandy loam Clay content--5 to 18 percent
Rock fragments--40 to 85 percent - 30 to 55 percent gravel, 5 to 40 percent cobbles, 0 to 5 percent stones
Reaction--6.8 to 8.4
Thickness--6 to 25 cm
Bk2 horizon (when present)
Value--4 or 5 dry; 2 or 3 moist
Chroma--2 to 4 dry or moist
Texture--loam, fine sandy loam, or sandy loam
Clay content--5 to 16 percent
Rock fragments--65 to 85 percent - 15 to 30 percent gravel, 45 to 65 percent cobbles, 0 to 10 percent stones
Reaction--7.2 to 7.8
COMPETING SERIES:
Agassiz (UT)--soils have 18 to 27 percent clay in the particle-size control section
Anatone (WA)--soils do not have accumulations of secondary calcium carbonate
Bluecanyon (OR)--soils do not have accumulations of secondary calcium carbonate
Bocker (WA)--soils are very shallow to lithic contact
Dipcreek ID)--soils do not have accumulations of secondary calcium carbonate
Falula (UT)--soils have a calcic horizon
Foxol (UT)--soils are slightly to moderately acid throughout the soil
Gomine (UT)--soils have more than 20 percent clay in the particle-size control section
Grink (NV)--soils have a calcic horizon
Hogsby (MT)--soils do not have accumulations of secondary calcium carbonate
Kenypeak (CA)--soils are slightly to moderately acid and do not have accumulations of secondary calcium carbonate
Little Pole (UT)--soils have greater than 18 percent clay in the particle-size control section and have accumulations of illuviated clay
Nayrib (ID)--soils are very shallow to lithic contact
Onaqui (UT)--soils have 18 to 27 percent clay in the particle-size control section
Rexmont (UT)--soils have 18 to 27 percent clay in the particle-size control section
Starglade (T)(OR)--soils are very shallow to lithic contact and have an influence of ash throughout the profile
Swanner (ID)--soils have violently effervescent accumulations of disseminated secondary calcium carbonate in the lower part of the soil profile
Van Wagoner (UT)--soils do not have accumulations of secondary calcium carbonate
GEOGRAPHIC SETTING:
Landform--mountain slopes and hillslopes
Elevation--1620 to 2,580 meters
Slopes--10 to 70 percent
Parent material--colluvium over residuum weathered from dolomite, limestone, and calcareous sandstone
Mean annual precipitation--350 to 930 millimeters
Mean annual temperature--2.2 to 6.0 degrees C
Frost-free period--50 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained, 5.0 to 50.0 um/sec.
USE AND VEGETATION: Lastchance soils are primarily used for wildlife habitat and livestock grazing. Potential native vegetation is bluebunch wheatgrass and mountain big sagebrush, and curl-leaf mahogony.
DISTRIBUTION AND EXTENT: Lastchance soils have small extent in southeastern Idaho; MLRAs 13, 47.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Caribou County Area, Idaho; 2011.
REMARKS: Diagnostic properties recognized in this pedon are:
Mollic epipedon--0 to 39 cm (A, Bk1 and Bk2 horizons)
Lithic contact--39 cm (R horizon)
Particle-size control section--25 to 39 cm
Lastchance soils have a frigid temperature regime and a xeric moisture regime.
Taxonomic version: Twelfth Edition, 2014
National Cooperative Soil Survey
U.S.A.