LOCATION CAPEHORN IDEstablished Series
TAXONOMIC CLASS: Medial over sandy or sandy-skeletal, mixed,
nonacid Aeric Cryaquepts
TYPICAL PEDON: Capehorn silt loam - on a 1 percent slope in a cutover forested area. When described, the soil was moist throughout. (Colors are for moist soil unless otherwise stated.)
01--2 to 1 inch; needles, leaves, and twigs.
02--1 inch to 0; decomposed organic matter.
0 to 1 inch; discontinuous light gray volcanic ash layer.
A--1 to 7 inches; dark yellowish brown (10YR 3/4) silt loam, yellowish brown (10YR 5/4) dry; moderate fine and medium granular structure; soft, very friable, slightly plastic; many very fine, common fine and medium roots; many very fine and common fine tubular pores; few fine iron and manganese stains; 5 percent fine pebbles; medium acid (pH 6.0); clear wavy boundary. (3 to 7 inches thick)
Bs--7 to 15 inches; dark yellowish brown (10YR 4/4) gravelly silt loam, light yellowish brown (10YR 6/4) dry; weak medium and coarse sub- angular blocky structure; soft, very friable, slightly plastic; common very fine, fine, and few medium roots; common very fine and few fine tubular pores; few fine iron and manganese stains; 15 percent fine pebbles; medium acid (pH 6.0); abrupt wavy boundary. (8 to 14 inches thick)
2Cg1--15 to 29 inches; light brownish gray (10YR 6/2) very gravelly loamy sand, white (10YR 8/2) dry; many medium and large prominent strong brown (7.5YR 5/6) mottles; single grain; loose; few very fine and fine roots; many very fine interstitial pores; 35 percent pebbles; slightly acid (pH 6.4); clear wavy boundary. (12 to 16 inches thick)
2Cg2--29 to 60 inches; light brownish gray (10YR 6/2) very gravelly sand, white (10YR 8/2) dry; many medium and large prominent strong brown (7.5YR 5/6) mottles; single grain; loose; few very fine roots; many very fine interstitial pores; 35 percent pebbles and 20 percent cobbles; slightly acid (pH 6.4).
TYPE LOCATION: Bonner County, Idaho; about 0.2 mile northwest of Indian Creek state campground near Priest Lake; 600 feet south and 1,350 feet west of the northeast corner, sec. 27, T. 61 N., R. 4 W
RANGE IN CHARACTERISTICS:
Volcanic ash mantle - 0 to 1 inch
Depth to high water table
Winter and spring - 0.0 to 1.5inches
Summer and fall - 1.5 to 5 feet
Average annual soil temperature - 40 to 44 degrees F.
Average summer soil temperature - about 43 degrees F.
Solum thickness - 12 to 20 inches
A horizon
Color hue - 10YR or 2.5Y
Value, moist - 3 or 4
Value, dry - 5 or 6
Chroma, moist or dry - 2 to 4
Coarse fragments - 0 to 15 percent
Reaction - strongly acid to medium acid
Bs horizon
Color hue - 10YR or 2.5Y
Value, moist - 3 to 5
Value, dry - 6 or 7
Chroma, moist or dry - 2 to 4
Texture - gravelly silt loam, silt loam, or very fine sandy loam Coarse fragments - 0 to 20 percent
Reaction - strongly acid to medium acid
Mottles - few faint-lower part of some pedons
2Cg horizon
Color hue - 10YR, 2.5Y, or 5Y
Value, moist - 5 or 6
Value, dry - 6 to 8
Chroma, moist or dry - 1 or 2
Mottles, hue - 5YR, 7.5YR, or 10YR
Value, moist - 4 or 5
Chroma, moist - 4 to 8
Rock fragments - 25 to 60 percent gravel, 0 to 20 percent cobbles, 0 to 5 percent stones
Reaction - medium acid to neutral
COMPETING SERIES: This is the Hoodoo series in another family. Hoodoo soils are medial and have a frigid temperature regime.
GEOGRAPHIC SETTING: Capehorn soils are on level or nearly level, small valley bottoms, low stream terraces, and floodplains. Elevations range from 2,075 to 4,200 feet. The soils formed in glacial outwash and alluvium with a mantle of volcanic ash and loess. Average annual air temperature ranges from 41 to 43 degrees F. Average annual precipitation ranges from 30 to 45 inches. The frost-free season is about 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bonner, Mission, Priestlake, Pywell, Treble, and the competing Hoodoo soils. Bonner, Priestlake, and Treble are well drained soils on adjacent terraces and uplands. Mission soils are somewhat poorly drained and a fragipan. Pywell soils are organic soils.
DRAINAGE AND PERMEABILITY: Poorly drained; slow runoff. Moderate permeability in the solum and very rapid in the substratum. The soils are commonly flooded during the winter and spring months for long periods. They have a high water table at depths of 0 to 20 during inches during winter and spring months.
USE AND VEGETATION: These soils are used for timber production, wildlife habitat, recreation, grazing and limited hay and pasture. Natural vegetation is mainly western hemlock, western redcedar, western white pine, black cottonwood, quaking aspen, paperbirch, sitka alder, and willow with an understory of myrtle pachystima, rose, northern twinflower, violet, piper anemone, goldthread, western thimbleberry, and horrid devilsclub.
DISTRIBUTION AND EXTENT: Northern Idaho. These soils are inextensive.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Bonner County, Idaho, 1981.