LOCATION TOLLGATE IDInactive Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Aridic Argixerolls
A11--0 to 3 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium granular structure; soft, very friable, slighty sticky and slightly plastic; many very fine to medium roots; many fine interstitial pores; neutral (pH 7.4); clear smooth boundary. (6 to 10 inches thick)
A12--3 to 11 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine to medium roots; many fine tubular pores; mildly alkaline (pH 7.4); clear smooth boundary. (6 to 10 inches thick)
A3--11 to 21 inches; brown (7.5YR 5/4) gravelly loam, dark brown (7.5YR 4/3) moist; weak coarse subangular blocky structure; hard, firm, sticky and slightly plastic; many very fine to medium roots; many fine tubular pores; mildly alkaline (pH 7.4); clear smooth boundary. (8 to 12 inches thick)
B21t--21 to 43 inches; pinkish gray (7.5YR 6/2) gravelly clay loam, dark brown (7.5YR 4/3, broken) and brown (7.5YR 5/4, crushed) moist; moderate fine and medium angular blocky structure; hard, firm, sticky, plastic; common fine and medium roots; many fine tubular pores; common thin clay films on surfaces of peds and rock fragments and in pores; mildly alkaline (pH 7.4); gradual smooth boundary. (14 to 26 inches thick)
B22t--43 to 54 inches; pinkish gray (7.5YR 6/2) very stony clay loam, dark brown (7.5YR 4/3, broken) and brown (7.5YR 5/3, crushed) moist; massive; hard, firm, sticky and plastic; few fine roots; many fine tubular pores; common thin clay films; mildly alkaline (pH 7.4).
TYPE LOCATION: Elmore County, Idaho; 100 feet west and 1,320 feet south of northeast corner section 23, T.2S., R.7E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 47 to 50 degrees F. and the mean summer temperature at a depth of 20 inches ranges from 65 to 70 degrees F. Tollgate soils are usually dry and are dry for about 50 to 70 consecutive days in late summer. The soils are moist for 60 to 80 consecutive days in the spring and early summer. The mollic epipedon ranges from 8 to 14 inches thick and the solum thickness is 30 to 50 inches. Strongly contrasting textures or bedrock are at depth greater than 40 inches. The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3. It is gravelly or cobbly loam or clay loam with 15 to 50 percent rounded and angular rock fragments. This horizon is slightly acid to mildly alkaline. The B2t horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry, 3 or 4 moist, and chroma of 2 through 4. It is clay loam or sandy clay loam in the fine earth fraction, has 18 to 35 percent clay, and has 35 to 50 percent angular or rounded rock fragments by volume. This horizon is neutral or mildly alkaline. The C horizon commonly contains 40 to 75 percent angular or rounded rock fragments and loamy interstitial material. It is neutral or mildly alkaline.
COMPETING SERIES AND THEIR DIFFERENTIAE: These are the Ashue, Babbington, Badenaugh, Collard, Haw, Searles and Shroe series. Ashue soils have contrasting very gravelly or cobbly sand below a depth of 30 inches. Babbington soils have sola 15 to 22 inches thick and have calcareous material at depths ranging from 15 to 22 inches. Badenaugh soils are slightly or medium acid in the lower part. Collard soils have sola 20 to 27 inches thick above very cobbly loamy sand. Haw soils have less than 15 percent rock fragments. Searles soils are less than 40 inches deep to bedrock. Shroe soils have more than 35 percent clay in the B2t horizon.
GEOGRAPHIC SETTING: Tollgate soils are on nearly level to steep alluvial and colluvial fans and mountain footslopes at elevations of 2,700 to 5,000 feet. Slopes of 3 to 15 percent are most common and range up o about 45 percent. The soils formed in alluvium and colluvium from rhyollitic and similar acid igneous rock sources. The climate is semiarid and summers are relatively dry. The average frost free season is 90 to 140 days and the mean annual precipitation is 11 to 14 inches including 1 to 4 feet of snow.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Haw, Rainey, Farrott, and Elmore soils all of which contain less than 35 percent rock fragments.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Used mostly for range and for wildlife habitat but some is used for irrigated or nonirrigated crops. Vegetation is bluebunch wheatgrass, Sandberg bluegrass, squirreltail, Idaho fescue, and big sagebrush. Crops are alfalfa, small grains, and improved pasture.
DISTRIBUTION AND EXTENT: Southwestern Idaho and adjoining regions. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Mayfield Soil Conservation District, Ada and Elmore Counties, Idaho, 1943.
REMARKS: Formerly classified as a Brown soil and later as an Aridic Calcic Argixeroll. The soils are usually noncalcareous and criteria for calcic intergrades has been changed.