LOCATION BUCKHOUSE MTEstablished Series
TYPICAL PEDON: Buckhouse flaggy ashy loam - native cover. (Colors are for dry soils unless otherwise noted.)
0i--0 to 3 inches; slightly decomposed grass roots and conifer needles--mulllike, neutral to moderately acid (pH 7.0 to 6.0).
A--3 to 26 inches; dark grayish brown (10YR 4/2) flaggy ashy loam, very dark brown (7.5YR 2/2) moist; strong very fine granular structure; soft, very friable, slightly sticky; wets with difficulty; many very fine roots; many very fine interstitial pores; 10 percent increasing with depth to 30 percent flagstones of argillite and quartzite; strongly acid (pH 5.3); clear wavy boundary. (18 to 30 inches thick)
2Bw--26 to 41 inches; light yellowish brown (10YR 6/4) extremely flaggy loam, dark yellowish brown (10YR 3/4) moist; weak very fine granular structure; soft, very friable, slightly sticky; many very fine roots that are matted between rocks in lower part; many very fine tubular pores; up to 1/8 inch thick layer of silt on some flagstones; 70 percent coarse fragments most of which are flagstones; strongly acid (pH 5.3); clear wavy boundary. (10 to 30 inches thick)
2C--41 to 75 inches; pale brown (10YR 6/3) very flaggy loam, olive brown (2.5Y 4/3) moist; weak fine granular structure; soft, very friable; few roots except for mats of roots on top of some flagstones; 1/8 inch thick layer of silt on some flagstones; 85 percent coarse fragments; strongly acid (pH 5.2).
TYPE LOCATION: Missoula County, Montana; approximately 1/2 mile east of microwave tower. 3/16 mile east, 1/16 mile north of SW corner, section 32, T.18N., R.24W.
RANGE IN CHARACTERISTICS: Solum ranges from 28 to 60 inches thick. Ash enriched mantle is 40 to 60 percent volcanic glass and ranges from 18 to 30 inches thick. The 10-to 40-inch section is sandy loam, loam or silt loam with 4 to 10 percent clay and 40 to 50 percent sand. Coarse and very coarse sands comprise 20 to 30 percent of the fine earth fraction. Coarse fragments range from 10 to 40 percent in the A1 horizon and 40 to 80 percent of the total soil volume in the B and C horizons. Soil reaction ranges from strongly to very strongly acid. Percent organic matter ranges from about 15 to 20 percent at the surface and decreases regularly to about one percent at depths ranging from 20 to 40 inches. Base saturation ranges from 20 to 40 percent in A1 horizons and from 15 to 25 percent in B and C horizons. Extractable iron ranges from 1.2 to 1.4 percent and extractable A1 ranges from 0.7 to 1.1 percent throughout the pedon. Buckhouse soils have estimated mean annual soil temperatures ranging from 40 to 44 degrees F. and average summer soil temperatures ranging from 50 to 55 degrees F. Hue ranges from 2.5Y to 5YR.
The A horizon has value of 3 through 5 dry and 2 to 3 moist and chroma of 2 through 4. Its cation exchange capacity ranges from 230 millequivalents per 100 grams of clay (organic matter included) at the surface to 200 milliequivalents at the base. Appreciable quantities--estimated at ranging from 40 to 60 percent--of volcanic glass shards occur throughout the A horizon in very fine sand and silt fraction.
Cation exchange capacity in the 2Bw and 2C horizons ranges from 140 to 175 milliequivalents per 100 grams of clay with organic matter included.
COMPETING SERIES: These are the similar Brickel, Buell, Nevine, Perma, Truefissure and Wishard series. Brickel, Buell and Perma soils lack volcanic glass shards. Brickel, Perma and Wishard soils have mollic epipedons and, in addition, Brickel soils have fine-grained gneiss at depths of about 30 inches and Wishard soils have yellowish brown mottlings in the B horizons. Nevine and Truefissure soils have ochric epipedons.
GEOGRAPHIC SETTING: Buckhouse soils occur on rolling to steep mountain slopes and on rounded ridge at elevations ranging from 5,500 to 8,000 feet at northern latitudes of about 47 degrees. The soils formed in residuum from Belt geologic series quartzite and argillites and modified by ashfall mantle at their type location. The climate is cold subhumid with estimated mean annual temperature ranging from 35 to 45 degrees F., summer from 45 to 55 degrees F. and mean annual precipitation ranging from 40 to 50 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coerock, Holloway, Truefissure and Wishard soils. These soils are under forest cover with ash-rich loess mantles.
DRAINAGE AND PERMEABILITY: Well-drained; moderate permeability.
USE AND VEGETATION: Primary use is for summer grazing for wildlife. Native vegetation is beargrass, senecio, lupine, yarrow, eriogonum, bearded wheatgrass, elksedge and wheeler bluegrass with thickets or open stands of lodgepole pine, whitebark pine, subalpine fir and Douglas-fir.
DISTRIBUTION AND EXTENT: Western Montana and eastern Idaho near the crest of the northern Rocky Mountains. Buckhouse soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Missoula County (St. Regis-Nine mile Area), Montana, 1970.
REMARKS: Diagnostic horizons and feature recognized in this pedon are:
Umbric epipedon, the zone from 3 to 26 inches; (A horizons)
Cambic horizon, , the zone from 26 to 41 inches; (2Bw horizons)
The upper 21 inches of the mineral soil is more than 23 percent volcanic glass. (A horizon)
This draft reflects a change in classification from Medial over loamy-skeletal, mixed, Entic Cryandepts to Ashy over loamy-skeletal, glassy over isotic Humic Vitricryands