LOCATION LAHOOD MTEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Aridic Haplustolls
TYPICAL PEDON: Lahood loam, 2 to 8 percent slope, rangeland (colors are for dry soil unless otherwise noted).
A--0 to 3 inches; brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and very fine roots; common fine and very fine pores; slightly alkaline (pH 7.8); abrupt smooth boundary. (3 to 5 inches thick)
Bw--3 to 11 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate medium and coarse prismatic structure; hard, firm, moderately sticky and moderately plastic; many fine and very fine roots; common fine pores; moderately alkaline (pH 8.4); abrupt smooth boundary. (5 to 9 inches thick)
Bk1--11 to 22 inches; very pale brown (10YR 7/3) sandy loam, brown (10YR 5/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common fine roots; few to common fine pores; 10 percent pebbles; violently effervescent; moderately alkaline (pH 8.4); clear way boundary. (8 to 14 inches thick)
Bk2--22 to 36 inches; pale brown (10YR 6/3) gravelly sandy loam, brown (10YR 5/3) moist; massive; loose, nonsticky and nonplastic; few to common fine and very fine roots; few fine pores; 25 percent pebbles; violently effervescent; strongly alkaline (pH 8.6). (4 to 15 inches thick)
R--36 inches; hard coarse grained sandstone.
TYPE LOCATION: Jefferson County, Montana; 200 feet north and 1,950 feet west of the SE corner of sec. 8, T. 1 N, R. 1 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 47 degrees F.
Moisture control section - between 8 and 24 inches; dry in all parts less than five-tenths and dry in some parts more than six-tenths of the cumulative days per year when the soil temperature at a depth of 20 inches is 41 degrees F and higher.
Mollic epipedon thickness - 7 to 14 inches.
Depth to Bk horizon - 10 to 15 inches.
Depth to bedrock - 20 to 40 inches.
Surface stones or boulders - 0 to 0.1 percent.
A horizon - Hue: 10YR or 7.5YR
Chroma: 2 or 3
Texture: loam or sandy loam
Clay content: 5 to 18 percent
Rock fragments: 0 to 35 percent--0 to 10 percent cobbles and stones; 0 to 25 percent pebbles
Reaction: pH 7.4 to 8.4
Bw horizon - Hue: 10YR or 7.5YR
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2 or 3
Texture: loam or sandy loam
Clay content: 5 to 18 percent
Rock fragments: 0 to 35 percent--0 to 10 percent cobbles and stones; 0 to 25 percent pebbles.
Reaction: pH 7.9 to 8.4
Bk1 and Bk2 horizons - Value: 6 or 7 dry; 5 or 6 moist
Texture: loam, coarse sandy loam or sandy loam
Clay content: 5 to 18 percent
Rock fragments: 5 to 35 percent--0 to 10 percent cobbles and stones; 5 to 25 percent pebbles
Calcium carbonate equivalent: 15 to 30 percent
Reaction: pH 7.9 to 9.0
COMPETING SERIES:
Anaconda (MT) - is very deep.
Chinook (MT) - is very deep.
Cozberg (MT) - is very deep.
Pring (CO) - is very deep.
Rhame (ND) - moderately deep to a paralithic contact.
Tinytown (CO) - 5YR and redder cambic horizons; does not have carbonates above a depth of 40 inches.
Ynot (MT) - is very deep.
GEOGRAPHIC SETTING:
Landforms - stream terraces, alluvial fans, ridges and sideslopes of hills and mountains.
Elevation - 3,500 to 5,500 feet.
Slope- 2 to 45 percent.
Parent material - local alluvium, colluvium or in residuum over sandstone, or igneous intrusive rock.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 14 inches, much of which falls as snow and spring rain.
Mean annual air temperature - 39 to 45 degrees F.
Frost-free period - 90 to 115 days.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.
USE AND VEGETATION: Lahood soils are used mainly as rangeland. The potential native vegetation is bluebunch wheatgrass, needleandthread, green needlegrass, and big sagebrush. A few areas have thin noncommercial stands of limber pine and Douglas fir.
DISTRIBUTION AND EXTENT: Lahood soils are of small extent in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jefferson County, Montana, 1998.
REMARKS: Soil interpretation record: MT1207, MT1208. Diagnostic horizons and features recognized in the pedon are: a mollic epipedon from the soil surface to 11 inches (A, Bw horizons); an accumulation of carbonates from 22 to 36 inches (Bk1, Bk2 horizon); hard sandstone or volcanic rock at a depth of 36 inches; a particle-size control section from 10 to 36 inches (Bw, Bk1, Bk2 horizons). Lahood soils have a frigid temperature regime and ustic moisture regime bordering on aridic.