LOCATION TAMELY MT

Established Series
Rev. PHO/DJP/BDM
10/2026

TAMELY SERIES

The Tamely series consists of very deep , well drained soils that formed in residuum and colluvium from metasedimentary rock with a thin mantel of volcanic ash. These soils occur on hills and mountain slopes. Slopes are 20 to 60 percent. Average annual precipitation is about 512 millimeters and average annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Ashy over sandy or sandy-skeletal, glassy over mixed Andic Haploxerepts

TYPICAL PEDON: Tamely gravelly ashy silt loam - forest cover. (Colors are of dry soil unless otherwise noted.)

Oi--0 to 3 centimeters; needles, twigs, decomposing organic materials.

Bw1--3 to 15 centimeters; pale brown (10YR 6/3) gravelly ashy silt loam, brown (10YR 4/3) moist, fine crumb structure; soft, very friable, slightly sticky; many fine and common medium roots; many fine interstitial pores; 30 percent angular gravel; slightly acid (pH 6.5); clear wavy boundary. (0 to 15 centimeters thick)

Bw2--15 to 41 centimeters; light yellowish brown (10YR 6/4) gravelly ashy silt loam, dark yellowish brown (10YR 4/4) moist; fine crumb structure; soft, very friable, slightly sticky; many fine, common medium and few coarse roots; many fine interstitial pores; 30 percent gravel; moderately acid (pH 5.8); clear wavy boundary. (15 to 36 centimeters thick)

2E--41 to 64 centimeters; very pale brown (10YR 8/3) extremely gravelly loamy fine sand, brown (10YR 5/3) moist; massive; slightly hard, very friable; many fine, few medium and coarse roots; common fine tubular pores; 65 percent gravel; strongly acid (pH 5.1); clear wavy boundary. (15 to 41 centimeters thick)

2E and B1--64 to 118 centimeters; very pale brown (10YR 8/2) extremely gravelly loamy sand, light brownish gray (10YR 6/2) moist; thin, discontinuous, wavy light yellowish brown (10YR 6/4) very gravelly loam lamellae; massive; slightly hard, very friable; common fine and medium roots; common fine tubular pores; 65 percent gravel; very strongly acid (pH 5.0); clear smooth boundary. (31 to 77 centimeters thick)

2E and B2--118 to 152 centimeters; very pale brown (10YR 8/2) extremely gravelly loamy sand, light brownish gray (10YR 6/2) moist; wavy, light yellowish brown (10YR 6/4), very gravelly loam lamellae 0.6 to 1.3 centimeters thick and 8 to 15 centimeters apart; massive; slightly hard, very friable; slightly sticky, slightly plastic in lamellae; few roots; 70 percent gravel; very strongly acid (pH 4.9).

TYPE LOCATION: Mineral County, Montana; approximately 183 meters south and 396 meters west of NE corner sec. 3, T.15N., R.24W.

RANGE IN CHARACTERISTICS: Tamely soils have mean annual soil temperature ranging from 5.0 to 7.0 degrees C. and average summer soil temperature ranging from 7 to 9 degrees C. under varying densities of forest cover. Angular and subangular hard rock fragments increase with increasing depth from 15 to 30 percent in thin loess mantle to 50 to 80 percent of volume in underlying horizons. The soils range from slightly acid or moderately acid in their ash-rich mantle B horizons to very strongly acid in their 2E and B horizons. The ash-rich overlay ranges from 18 to 36 centimeters thick. It has hue of 7.5YR or 10YR, dry value of 5 or 6 and chroma of 3 through 6. This horizon has bulk density of .65 to .85 grams/cc, base saturation of 20 to 50, and cation exchange capacity relative to clay ranges from 1 to 3. It has 5 to 10 percent clay and 40 to 70 percent silt plus very fine sand. The E horizon portions of the horizon have hue of 2.5Y or 10YR, value of 6 through 8, and chroma of 1 through 3. The lamellae have hue of 7.5YR or 5YR, value of 6 or 7 and chroma of 2 through 4. The buried horizons range from loamy fine sand to loamy sand. They have estimated bulk density of 1.5 to 2, estimated base saturation of 50 to 90 percent and cation exchange capacity of 0.5 to 1 gram/gram of clay. Lamellae range from 0.8 to 1.3 centimeters thick and comprise 1 to 10 percent of the soil. These have from 15 to 25 percent clay and 30 to 50 percent silt.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:
Landform - hills and mountain slopes.
Elevation - 550 to 1250 meters.
Slope - 0 to 35 percent.
Parent material - volcanic ash over colluvium or residuum derived from metasedimentary rock.
Climate - long, cold winters; moist springs; short warm summers.
Mean annual precipitation - 307 to 486 mm.
Mean annual air temperature - 4.0 to 7.0 degrees C.
Frost-free period - 70 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: Tamely soils are associated with Jazzbo and Yellowbay. These soils lack the silty ash-rich surface horizons.

DRAINAGE AND PERMEABILITY: Well-drained; moderately rapid permeability.

USE AND VEGETATION: Principal use is for forest products, wildlife habitat, and watershed. Vegetation is mainly an overstory of Douglas-fir, western larch, lodgepole pine, Engelmann spruce, and an understory of beargrass, kinnikinnick, huckleberry, and sedges.

DISTRIBUTION AND EXTENT: Tamely soils are of limited extent in western Montana and eastern Idaho.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana.

SERIES ESTABLISHED: St. Regis-Ninemile Area, Montana, 1970.

The 8/2026 description reflects a change in classification from Ashy over sandy or sandy-skeletal, glassy over mixed Andic Haplocryepts to Ashy over sandy or sandy-skeletal, glassy over mixed, frigid Andic Haploxerepts.

National Cooperative Soil Survey
U.S.A.