LOCATION CADOTTE MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustic Haplocryalfs
TYPICAL PEDON: Cadotte gravelly loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 2 inches; undecomposed and slightly decomposed forest litter of needles and twigs.
A--2 to 5 inches; dark gray (10YR 4/1) gravelly loam, very dark gray (10YR 3/1) moist; weak very thin platy structure parting to weak very fine granular; soft, very friable, slightly sticky and nonplastic; many very fine roots; 20 percent pebbles; moderately acid (pH 5.6); abrupt smooth boundary. (2 to 4 inches thick)
Bt/A--5 to 10 inches; B part (80 percent) brown (10YR 5/3) gravelly loam, dark brown (10YR 4/3) moist; A part (20 percent) grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate medium and fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots and few medium roots; many very fine tubular band interstitial pores; few distinct clay films on faces of peds; 30 percent pebbles; moderately acid (pH 5.8); clear smooth boundary. (3 to 6 inches thick)
Bt1--10 to 20 inches; yellowish brown (10YR 5/4) very gravelly loam, dark yellowish brown (10YR 4/4) moist; moderate medium and fine subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; common very fine roots and few medium roots; many very fine tubular and interstitial pores; common distinct clay films on faces of peds; 40 percent pebbles and 10 percent cobbles; moderately acid (pH 5.8); clear smooth boundary. (8 to 15 inches thick)
Bt2--20 to 25 inches; yellowish brown (10YR 5/4) very gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; moderate medium and fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common fine and very fine roots, and few medium roots; many very fine tubular and interstitial pores; few faint clay films on faces of peds; 45 percent pebbles and 10 percent cobbles; moderately acid (pH 5.8); gradual smooth boundary. (3 to 8 inches thick)
Bt3--25 to 34 inches; brown (10YR 5/3) extremely gravelly sandy loam, dark brown (10YR 4/3) moist; weak medium and fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common fine and very fine roots and few medium roots; many very fine tubular and interstitial pores; distinct clay bridging of sand grains; 45 percent pebbles and 20 percent cobbles; slightly acid (pH 6.5); gradual smooth boundary. (3 to 10 inches thick)
2Bk--34 to 60 inches; brown (10YR 5/3) extremely gravelly loamy sand, dark brown (10YR 4/3) moist; single grain; loose; slightly sticky and nonplastic; few very fine roots; 45 percent pebbles and 20 percent cobbles; disseminated lime, strongly effervescent; continuous faint lime casts on undersides of fragments; slightly alkaline (pH 7.8).
TYPE LOCATION: Lewis and Clark County, Montana; 2,500 feet east and 2,450 feet north of the SW corner of sec. 24, T. 15 N., R. 8 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 38 to 44 degrees F.
Moisture control section - between 4 and 12 inches.
Depth to 2Bk horizon - 20 to 40 inches.
The dark colored A horizon when mixed to a depth of 7 inches will not meet the requirements for a mollic epipedon.
A horizon - Value: 4, 5, or 6 dry; 3 or 4 moist
Chroma: 1, 2, or 3
Clay content: 15 to 25 percent
Rock fragments: 15 to 35 percent pebbles
Reaction: pH 5.6 to 6.0
Bt/A horizon - Value: B part 5 or 6, A part 5 or 6 dry; B part 3 or 4, A part 3 or 4 moist
Chroma: B part 3 or 4, A part 2 or 3
Clay content: 15 to 25 percent
Rock fragments: 15 to 35 percent pebbles
Reaction: pH 5.6 to 6.0
Bt1 and Bt2 horizons - Hue: 10YR to 7.5YR
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 3 or 4
Texture: loam, sandy loam, or clay loam
Clay content: 18 to 30 percent
Rock fragments: 45 to 65 percent--40 to 50 percent pebbles, 5 to 15 percent cobbles
Reaction: pH 5.6 to 6.0
Bt3 horizon - Hue: 10YR or 7.5YR
Value: 5 or 6 dry, 4 moist
Chroma: 2 or 3
Clay content: 5 to 20 percent
Rock fragments: 50 to 70 percent - 40 to 50 percent pebbles, 10 to 20 percent cobbles
Reaction: pH 5.6 to 7.3
2Bk horizon - Hue: 10YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2, 3, or 4
Texture: sand or loamy sand
Clay content: 0 to 5 percent
Rock fragments: 60 to 75 percent--40 to 65 percent pebbles, 10 to 20 percent cobbles
Calcium carbonate equivalent - 5 to 15 percent
Reaction: pH 7.4 to 8.4
COMPETING SERIES:
Cloud Peak (WY) - moderately deep to lithic bedrock.
Cundiyo (NM) - less than 15 percent clay in the argillic horizon; the upper boundary of the argillic horizon is 10 inches or more below the soil surface.
Goosepeak (CO) - does not have a horizon of secondary carbonate accumulation.
Guffey (CO) - moderately deep to paralithic bedrock.
Hyattville (WY) - moderately deep to lithic bedrock.
Kimpton (MT) - moderately deep to lithic bedrock.
Lake Creek (WY) - moderately deep to lithic bedrock.
Lakehelen (WY) - moderately deep to lithic bedrock.
Lulude (CO) - moderately deep to lithic bedrock.
Tepecreek (MT) - moderately deep to paralithic contact; deep to lithic bedrock.
GEOGRAPHIC SETTING:
Landform - stream terraces in mountain valleys.
Elevation - 4,500 to 5,500 feet.
Slope - 0 to 4 percent.
Parent material - alluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 20 to 25 inches, most of which falls as snow and spring rain.
Mean annual air temperature - 36 to 42 degrees F.
Frost-free period - 50 to 70 days.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability above the sandy-skeletal material and rapid in the sandy-skeletal material.
USE AND VEGETATION: Cadotte soils are used mainly for woodland and understory grazing. Potential native vegetation is mainly lodgepole pine and Douglas fir with an understory of pinegrass, elk sedge, rough fescue, Idaho fescue, dwarf huckleberry, Oregon-grape, and other shrubs, forbs, and grasses.
DISTRIBUTION AND EXTENT: Cadotte soils are inextensive in the mountain valleys of western Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lewis and Clark County Area, Montana, 1991; proposed in Lewis and Clark County, Montana, 1988. Cadotte is the name of a local creek.
REMARKS: Soil interpretations record: MT1160. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from 2 to 10 inches (A and Bt/A horizons); an argillic horizon from 10 to 25 inches (Bt1, Bt2 horizon); and a sandy-skeletal 2Bk horizon below a depth of 34 inches. The particle-size control section is the argillic horizon. Cadotte soils have a cryic temperature regime and an ustic moisture regime.