LOCATION ELWOOD                  UT+MT WY

Established Series
Rev. VLM/MEO/KLS
09/2022

ELWOOD SERIES

The Elwood series consists of moderately deep, well drained soils that formed in residuum and colluvium from derived from limestone. These soils are on moderately steep to very steep mountain slopes. Slopes are 10 to 60 percent. Mean annual precipitation is about 710 mm and mean annual air temperature is about 4 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Typic Argicryolls

TYPICAL PEDON: Elwood silt loam, native conifer. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 5 cm; needles and twigs.

A--5 to 33 cm; brown (10YR 5/3) heavy silt loam, dark brown (7.5YR 3/3) moist; moderate medium subangular blocky structure that parts to moderate medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium and few large roots; few fine discontinuous random inped pores; moderately acid (pH 6.0); clear wavy boundary. (20 to 40 cm thick)

Bt1--33 to 71 cm; brown (7.5YR 5/4) cobbly silty clay brown, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, firm, sticky and slightly plastic; common fine and medium roots; few fine discontinuous random inped pores; common thin clay film in pores and on surface of peds; 20 percent cobbles; neutral (pH 6.6); clear wavy boundary. (20 to 50 cm thick)

Bt2--71 to 97 cm; brown (7.5YR 5/4) very cobbly light silty clay loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common fine and medium roots; common thin clay films; 80 percent cobbles and gravel, fractured limestone rock fragments; neutral (pH 7.0); abrupt wavy boundary.

R--97 to 110 cm; fractured limestone bedrock.

TYPE LOCATION: Cache County, Utah; about 3 km south and 1.5 km east of Beaver Mountain; about 610 meters north and 610 meters east of the SW corner of section 20, T.14N., R.4E.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--3 to 7 degrees C
Mean summer soil temperature at a depth of 50 cm--8 to 12 degrees C
Thickness of mollic epipedon--18 to 40 cm
Depth to bedrock--50 to 100 cm
Rock fragments--dominantly angular cobble and gravel of limestone lithology
The Bt horizon may extend into cracks in the limestone bedrock.

A horizon
Hue--10YR or 7.5YR
Value--4 or 5 dry, 2 or 3 moist
Chroma--2 or 3
Reaction--pH 5.6 to 6.5

Bt horizon(s)
Hue--10YR or 7.5YR
Value--4 through 6 dry, 3 or 4 moist; It has value of 4 moist below a depth of 50 cm
Chroma--3 or 4
Clay content--more than 18 percent
Clay films--thin common to continuous clay films on faces of peds and in pores
Texture--cobbly and cobbly silty clay loam to very gravelly heavy loam with more than 18 percent clay
Rock fragment content--more than 35 percent cobbles and gravel in the upper 50 cm of the Bt horizons
Reaction--pH 6.1 to 7.3

COMPETING SERIES: These are the Bickmore, Blaine, Buena Vista, Ess, Hourglass, Libeg, Mult, Nathrop, Rammel, Tahquats, Thiel, and Woodhall series. Bickmore, Blaine, Buena Vista, Nathrop, Rammel, and Thiel soils have horizons of secondary carbonate accumulation. Also, Bickmore soils have mollic epipedons thicker than 40 cm. Ess, Hourglass, Libeg, Tahquats, and Thiel soils are deeper than 100 cm to bedrock. Mult soils have less than 15 percent cobbles and gravel in the argillic horizon. Woodhall soils have rock fragments that are mainly more than 250 mm in diameter and lack limestone fragments.

GEOGRAPHIC SETTING:
Landform--moderately steep to very steep mountain slopes
Elevation--2275 to 2750 meters
Slope--10 to 60 percent
Parent Material--residuum and colluvium from limestone
Climate--moist subhumid
Mean annual precipitation--640 to 890 mm
Mean annual air temperature--0 to 6 degrees C
Mean summer air temperature--13 to 14 degrees C
Frost free period--75 to 90 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.

USE AND VEGETATION: Elwood soils are used for timber production and for watershed and the native vegetation is alpine fir, Douglas fir, and some Englemann spruce.

DISTRIBUTION AND EXTENT: Elwood soils are moderately extensive in the mountains of central Utah, central Montana and western Wyoming; MLRAs 43B and 47

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

SERIES ESTABLISHED: Cache County, Utah, 1972

REMARKS: Converted to metric, updated formatting, and O horizons were updated to start at zero. Competing series section was not updated. 8/2022

Elwood soils were formerly classified as Brunizems.

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National Cooperative Soil Survey
U.S.A.