LOCATION ROYGORGE                CO

Established Series
Rev. GB/JPP/KLS
09/2022

ROYGORGE SERIES

Roygorge series consists of shallow or very shallow, well drained soils that formed in residuum derived from gneiss, sandstone, and granite on mountain slopes and footslopes of mountains. Slope ranges from 5 to 50 percent. Mean annual precipitation is about 310 mm and mean annual air temperature is about 10 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Lithic Ustic Haplargids

TYPICAL PEDON: Roygorge very gravelly sandy clay loam - on a 46 percent slope in an area of pinyon and juniper. (Colors are for dry soil unless otherwise stated.)

Oe--0 to 3 cm; partially decomposed pinyon and juniper litter. (0 to 5 cm thick)

A--3 to 8 cm; brown (7.5YR 4/2) very gravelly sandy clay loam, dark brown (7.5YR 3/2) moist; moderate medium granular structure; soft, very friable, slightly sticky and nonplastic; 35 percent pebbles, 15 percent cobbles; neutral; abrupt smooth boundary. (5 to 13 cm thick)

Bt1--8 to 16 cm; brown (7.5YR 4/4) very gravelly sandy clay loam, dark brown (7.5YR 3/4) moist; weak medium prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, sticky and slightly plastic; many prominent clay films on rocks and few faint clay films on faces of peds; 45 percent pebbles, 10 percent cobbles; neutral; gradual irregular boundary. (8 to 30 cm thick)

Bt2--16 to 31 cm; strong brown (7.5YR 4/6) very gravelly sandy clay loam, dark brown (7.5YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; few faint clay films on faces of peds and on rocks; 45 percent pebbles, 10 percent cobbles; neutral; clear irregular boundary. (0 to 23 cm thick)

Bkm--31 to 34 cm; indurated calcium carbonate. (0 to 3 cm thick)

R--34 cm; fractured gneiss.

TYPE LOCATION: Fremont County, Colorado; about 245 meters north and 700 meters east of the southwest corner of sec. 35, T. 18 S., R. 71 W.; U.S.G.S. Royal Gorge quad.; Lat. 38 degrees, 25 minutes, 59 seconds N., and Long. 105 degrees, 18 minutes, 06 seconds W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--9 to 12 degrees C
Mean summer soil temperature--19 to 23 degrees C
Depth to bedrock--20 to 50 cm
Depth to the base of the argillic horizon--20 to 50 cm

Particle-size control section:
Fine and coarser sands comprise 50 percent or more of the fine-earth fraction.
Rock fragment content--35 to 75 percent and are mainly pebbles, gravel and cobbles; however, a few stones may be present in some pedons
Reaction--pH 6.1 to 8.4

A horizon
Hue--10YR or 7.5YR
Value--4 or 5 dry, 3 or 4 moist
Chroma--1 through 3

Bt horizon
Hue--10YR through 5YR
Value--4 through 6 dry, 3 or 4 moist
Chroma--3 through 6
Rock fragment--35 to 75 percent
Clay content--20 to 35 percent
Texture--sandy clay loam or clay loam

COMPETING SERIES: These are the Puertecito (NM), Quazo (UT), and Wyva (NV) series.

Puertecito soils have an average sand content of less than 50 percent.

Quazo soils lack a consistent K horizon. In addition, the Quazo soils are usually dry in the moisture control section during the period when the soil temperature is above 5 degrees C.

Wyva soils have total sand content of less than 60 percent and are moist less than 60 consecutive days April through September.

GEOGRAPHIC SETTING:
Landform--mountain slopes and footslopes of mountains
Elevation--1575 to 2125 m
Slope--5 to 50 percent
Parent material--residuum derived from gneiss, sandstone or granite
Mean annual precipitation--280 to 360 mm
Mean annual air temperature--8 to 11 degrees C
Frost-free period--130 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderate permeability

USE AND VEGETATION: These soils are used for noncommercial woodland, livestock grazing, and wildlife habitat. Principal vegetation is an overstory of pinyon and juniper and an understory of Indian ricegrass, Scribner needlegrass, sideoats grama, blue grama, and true mountain mahogany.

DISTRIBUTION AND EXTENT: Roygorge soils are moderately extensive in the foothills of the Southern Rocky Mountains of central and western Colorado and the foothills and plateaus of eastern Utah; MLRAs 36 and 49

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

SERIES ESTABLISHED: Fremont County (Fremont County Area), Colorado, 1988

REMARKS: Diagnostic horizons and features recognized in this soil include:
Ochric epipedon--3 to 8 cm (A horizon)
Argillic horizon--8 to 31 cm (Bt1 and Bt2 horizons)
Zone of cemented calcium carbonate--31 to 34 cm (Bkm horizon)
Lithic contact--34 cm to hard bedrock (R horizon)
Rock fragment content--more than 35 percent in the particle-size control section

Particle-size control section--8 to 31 cm (Bt1 and Bt2 horizons)

Roygorge soils have a mesic temperature regime and an aridic soil moisture regime bordering on ustic.

The classification was changed from a Lithic Ustollic subgroup to a Lithic Ustic subgroup to be compatible to the 1994 Amendments to Soil Taxonomy. 03/2003

The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Lakewood MLRA office, without review of the soil series property data.

Converted to metric, updated formatting, and O horizons were updated to start at zero. Competing series section was not updated. 9/2022

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National Cooperative Soil Survey
U.S.A.