LOCATION REGNAPS WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Hapludalfs
TYPICAL PEDON: Regnaps loam-on a hill footslope of 6 percent; utilized as rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; pale brown (10YR 6/3) loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common fine roots; neutral (pH 7.0); clear smooth boundary. (2 to 5 inches thick)
Bt1--4 to 9 inches; brown (10YR 5/3) clay loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common fine roots; few thin clay films on faces of peds; neutral (pH 7.2); clear smooth boundary.
Bt2--9 to 16 inches; brown (10YR 5/3) clay loam, dark yellowish brown (10YR 4/4) moist; moderate coarse prismatic structure parting to strong medium angular blocky; hard, firm, sticky and plastic; few fine roots; common thin clay films on faces of peds; slightly alkaline (pH 7.4); clear smooth boundary. (Combined thickness of Bt is 12 to 25 inches.)
C--16 to 21 inches; pale brown (10YR 6/3) loam dark yellowish brown (10YR 4/4) moist; massive slightly hard, friable, slightly sticky and nonplastic; few fine roots; slightly alkaline (pH 7.6); abrupt wavy boundary. (6 to 25 inches thick)
Cr--21 inches; noncalcareous, argillaceous sandstone.
TYPE LOCATION: Weston County, Wyoming; about 300 feet east and 150 feet south of the northwest corner of sec. 4, T. 46 N., R. 62 W. Skull Creek Quadrangle. 44 degrees 0 minutes 12 seconds north latitude and 104 degrees 18 minutes 56 seconds west longitude.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 42 to 46 degrees F. The mean summer soil temperature is 59 to 63 degrees F. Depth to bedded sandstone is 20 to 40 inches. Depth to the base of the argillic horizon is 14 to 26 inches. The soil is noncalcareous throughout. The soil is moist in all parts of the moisture control section in April, May, and June but is dry in all parts for 60 consecutive days during the period July 15 to October 15.
The A horizon has hue of 2.5Y or 10YR, value of 5 or 6 dry, 3 or 4 moist, and chroma of 2 or 3. It is loam or sandy loam. Reaction is neutral or slightly alkaline.
The Bt horizon has hue of 2.5Y or 10YR, value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 through 4. It is clay loam or sandy clay loam and averages 27 to 35 percent clay and less than 35 percent fine sand or coarser. Reaction is neutral or slightly alkaline.
The C horizon has hue of 2.5Y or 10YR, value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 through 4. It is loam or sandy loam. Coarse sandstone fragments less than 3 inches in diameter range from 0 to 15 percent. Reaction is neutral or slightly alkaline.
The Cr horizon is a paralithic contact to well consolidated, noncalcareous, argillaceous sandstone. Some discontinuous layers of hard sandstone may occur in some strata beneath the paralithic contact.
COMPETING SERIES: These are the Alderon, Allens Park, Bayerton, Bondoe(T), Elbeth, Elmark(T), Fairport, Ferball(T), Foreleft(T), Gateson, Haugan, Lakoa, Lengby(T), Lumpgulch(T), Nebish, Onaway, Plome, Rule(T), and Snellman(T). Alderon, Gateson, and Lengby soils have an E horizon. Allen Park, Bayerton, Fairport, Lumpgulch and Rule soils have a lithic contact at 20 to 40 inches. Bondoe soils are loamy-skeletal below the argillic horizon. Elbeth, Haugan, Lakoa, and Plome soils are very deep. Elmark soils have a paralithic and a lithic contact above 60 inches. Ferball, Foreleft and Nebish soils are very deep, in addition the Nebish soils formed in Wisconsin age glacial till. Snellman soils have moderately acid or slightly acid reaction in the argillic horizon.
GEOGRAPHIC SETTING: Regnaps soils are on rock controlled hillslopes, fan aprons, and pediments. Slopes range from 2 to 20 percent. Elevations range from 5,600 to 7,200 feet. The average annual precipitation is about 16 inches but ranges from 15 to 19 inches. Over half the annual precipitation falls as snow or rain in the months of April, May, and June. The mean annual temperature is 41 degrees F. but ranges from 38 to 43 degrees F. The frost-free season is 85 to 110 days, but frost may occur in any month except August.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Crownest and Norkool soils. The Crownest soils occupy steeper slopes and have lithic contacts at less than 20 inches. The Norkool soils occupy snowpack or run in areas and have mollic epipedons.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Used for rangeland. Native vegetation is needleandthread, western wheatgrass, blue grama, and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: Northeastern Wyoming within or adjacent to the Black Hills. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Weston County, Wyoming; 1983.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 4 inches, (A)
Argillic horizon - 4 to 16 inches (Bt1,Bt2)
Paralithic contact - 21 inches (Cr)
MLRR- G
SIR- WY0507