LOCATION MOHAGGIN MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Andic Dystrocryepts
TYPICAL PEDON: Mohaggin bouldery ashy very fine sandy loam, forested. (Colors are for dry soil unless otherwise stated.
0i--0 to 2 inches; undecomposed needles and twigs.
0e--2 to 5 inches; partially decomposed neddles and twigs. (O horizons are 2 to 5 inches thick.)
A--5 to 14 inches; light yellowish brown (10YR 6/4) bouldery ashy very fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure parting to weak fine granular; soft, very friable, nonsticky and nonplastic; many very fine and fine and common medium roots; common very fine tubular pores; 10 percent boulders, 5 percent cobbles, and 15 percent gravel; slightly acid (pH 6.3); clear wavy boundary. (7 to 12 inches thick)
2Bw--14 to 22 inches; brown (10YR 4/3) very gravelly sandy loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine and common medium roots; common fine and medium tubular pores; 1 percent boulders, 15 percent cobbles and 30 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (5 to 10 inches thick)
2BC--22 to 32 inches; pale brown (10YR 6/3) very gravelly sandy loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine and fine and few medium roots; common fine tubular pores; 1 percent boulders, 15 percent cobbles, and 30 percent gravel; slightly acid (pH 6.1); clear wavy boundary. (9 to 11 inches thick)
2C--32 to 60 inches; very pale brown (10YR 7/3) very cobbly loamy sand, pale brown (10YR 6/3) moist; weak medium subangular blocky structure parting to single grain; soft, friable, nonsticky and nonplastic; common very fine and few fine and medium roots; common very fine interstitial pores; 1 percent boulders, 20 percent cobbles and 20 percent gravel; slightly acid (pH 6.1).
TYPE LOCATION: Deer Lodge County, Montana; about 400 feet east and 1,300 feet south of the northwest corner of sec. 35, T. 4 N., R. 12 W.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 39 to 45 degrees F
Moisture control section - between 8 and 24 inches; udic moisture regime
Base saturation - less than 60 percent in one or more horizons between 10 and 30 inches
A horizon
Value: 5 or 6 dry, 3 or 4 moist
Clay content: 5 to 10 percent
Rock fragments: 15 to 35 percent--5 to 10 percent boulders or stones, 0 to 5 percent cobbles, 15 to 25 percent gravel
Reaction: pH 5.1 to 6.5
Acid oxalate Al+1/2 Fe: greater than 1 percent (estimated)
Bulk density - 0.80 to 0.95g/cc in fine earth fraction
2Bw and 2BC horizons
Value: 3 to 5 moist, 4 to 6 dry
Chroma: 2 or 3
Clay content: 3 to 6 percent
Rock fragments - 35 to 60 percent--0 to 5 percent stones or boulders, 5 to 15 percent cobbles, 30 to 50 percent gravel
Reaction: pH 5.1 to 6.5
2C horizon
Value: 5 or 6 moist, 6 or 7 dry
Chroma: 2 or 3
Texture: loamy sand or coarse sand
Clay content: 0 to 5 percent
Rock fragments: 35 to 70 percent--0 to 5 percent stones or boulders, 20 to 35 percent cobbles, 15 to 35 percent gravel
Reaction: pH 5.1 to 6.5
COMPETING SERIES:
Goodlow (OR) - has an umbric epipedon 7 to 18 inches thick
Growden (WA) - has an umbric epipedon more than 20 inches thick
Hun (ID) - deep to a paralithic contact
Rubycreek (ID) - has medial textural modifiers in the A and Bw horizons
Rustlerpeak (OR) - moderately deep to a paralithic contact; has an umbric epipedon 10 to 20 inches thick
Threebutte (WA) - moderately deep to a lithic contact
GEOGRAPHIC SETTING:
Landform- mountains
Elevation - 5,600 to 9,200 feet
Slope - 8 to 80 percent
Parent material - volcanic ash over granite colluvium
Climate - long, cold winters, moist springs, short, cool summers
Average annual precipitation - 20 to 40 inches
Average annual temperature - 37 to 43 degrees F
Frost free period - 30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Comad, Cowood, Mooseflat, and Worock soils. Comad soils are on mountains and are sandy-skeletal. Cowood soils are on mountains and are shallow to bedrock. Mooseflat soils are in drainageways and are very poorly drained. Worock soils are on mountains and have argillic horizons.
DRAINAGE AND PERMEABILITY: Well-drained; moderately rapid over rapid permeability.
USE AND VEGETATION: Mohaggin soils are used for timber-production, wildlife habitat, recreation, and watershed. A few areas are used for limited livestock grazing. Natural vegetation is mainly lodgepole pine, subalpine fir, whitebark pine and Douglas fir depending on elevation and aspect. Understory vegetation consists of grouse whortleberry, elk sedge, pinegrass, common juniper, common beargrass, and blue huckleberry.
DISTRIBUTION AND EXTENT: Southwestern Montana. The series is not extensive. Mohaggin is a coined name for Mount Haggin, a mountain in Deer Lodge County.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Deer Lodge County, Montana, 2003.
REMARKS: Diagnostic horizons and features recognized in this pedon are an ash influenced layer from 5 to 14 inches (A horizon); an ochric epipedon from the soil surface to 7 inches (Oi, Oe, and A horizons); a cambic horizon from 14 to 32 inches (2Bw and 2BC horizons); a particle-size control section from 10 to 40 inches below the mineral soil surface.
3/28/08- In review of this description, further investigation is needed to determine base saturation (for the depth between 25 to 75 cm below the mineral soil surface) to classify as Dystrocryepts.