LOCATION TRAMPAS                 NM+CO

Established Series
Rev. JOC/JAW/KLS
09/2022

TRAMPAS SERIES

The Trampas series consists of deep, well drained soils that formed in alluvium weathered from mixed sediments. Trampas soils are on dissected old alluvial fans and plains and have slopes of 15 to 50 percent. The mean annual precipitation is about 560 mm and the mean annual air temperature is about 7 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, mixed, superactive, frigid Typic Haplustalfs

TYPICAL PEDON: Trampas cobbly sandy loam, forested. (Colors are for dry soil unless otherwise noted.)

Oe--0 to 3 cm; needles, leaves, twigs, etc., in various stages of decomposition.

A--3 to 8 cm; grayish brown (10YR 5/2) cobbly sandy loam, very dark grayish brown (10YR 3/2) moist; weak very fine and fine granular structure; soft, friable; many very fine and fine roots; many very fine interstitial pores; 25 percent cobbles, 30 percent gravel; neutral (pH 6.6); abrupt smooth boundary. (5 to 10 cm thick)

E--8 to 21 cm; light gray (10YR 7/2) gravelly sandy loam, yellowish brown (10YR 5/4) moist; weak very fine and fine roots; many very fine interstitial pores; 30 percent gravel; slightly acid (pH 6.4); clear smooth boundary. (13 to 25 cm thick)

BEt--21 to 29 cm; brown (10YR 5/3) extremely cobbly sandy clay loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few fine, medium, and coarse roots; many very fine interstitial pores; many thin clay films on peds and common thin clay films on rock fragments; 30 percent cobbles, 40 percent gravel; slightly acid (pH 6.4); clear smooth boundary. (10 to 15 cm thick)

Bt--29 to 93 cm; reddish brown (5YR 5/3) extremely gravelly clay, reddish brown (5YR 4/3) moist; moderate fine and medium subangular blocky structure; very hard, very firm, sticky and plastic; few very fine, fine and medium roots; many very fine tubular pores; common thick clay films on peds and on rock fragments; 60 percent gravel and 20 percent cobbles; slightly acid (pH 6.2); gradual smooth boundary. (23 to 35 cm thick)

CBt--93 to 129 cm; yellowish red (5YR 5/6) extremely cobbly sandy clay loam, reddish brown (5YR 4/4) moist; weak fine and medium subangular blocky structure; very hard, firm, sticky and plastic; few very fine roots; common very fine tubular pores; common thick clay films on peds and on rock fragments; 40 percent gravel and 40 percent cobbles; moderately acid (pH 6.0); gradual smooth boundary. (25 to 35 cm thick)

C--129 to 159 cm; reddish brown (5YR 5/4) extremely cobbly light sandy clay loam, reddish brown (5YR 4/4) moist; massive; very hard, firm, slightly sticky and slightly plastic; 55 percent cobbles, 40 percent gravel; moderately acid (pH 6.0).

TYPE LOCATION: Rio Arriba County, New Mexico, NW1/4 SE1/4 section 30, T.22N., R.11E.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--6 to 8 degrees C
Mean summer soil temperature--11 to 13 degrees C
Solum thickness--100 to 150 cm

A horizon
Value--5 through 7 dry, 3 through 5 moist
Chroma--2 or 3
Texture--sandy loam or loam
Rock fragment content--20 to 60 percent

Bt horizon(s)
Hue--5YR or 7.5YR
Value--4 or 5 dry or moist
Chroma--3 through 6
Texture--clay or sandy clay
Rock fragment content--50 to 80 percent

C horizon
Hue--5YR or 7.5YR
Value--5 or 6 dry or moist
Texture--sandy clay loam or sandy loam
Rock fragment content--75 to 95 percent

COMPETING SERIES: These are the Bignell, Crest and Pinata series. Bignell soils have sola more than 150 cm thick and have E/Bt horizons. Crest soils have limestone at depths of less than 100 cm. Pinata soils have rock fragments that are mainly of stone size.

GEOGRAPHIC SETTING:
Landform--dissected alluvial fans and alluvial plains
Elevation--2275 to 2750 meters
Slope--15 to 50 percent
Parent material--transported material from mixed sources
Mean annual precipitation--460 to 640 mm and about 60 percent of the precipitation occurs as snow and winter rain
Mean annual air temperature--7 degrees C
Mean summer air temperature--13 degrees C

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

DRAINAGE AND PERMEABILITY: Well drained; slow permeability

USE AND VEGETATION: Used for timber production, seasonal grazing, watershed, recreation, and wildlife habitat. Vegetation is mainly ponderosa pine with an understory of creeping barberry, buckwheat, yarrow, squirreltail, pine dropseed, and Arizona fescue.

DISTRIBUTION AND EXTENT: Trampas soils are moderately extensive northern New Mexico and southwest Colorado; MLRAs 48A and 48B

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

SERIES ESTABLISHED: Taos Area, New Mexico, 1976

REMARKS: Converted to metric, updated formatting, and O horizons were updated to start at zero. Competing series section was not updated. 7/2022

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National Cooperative Soil Survey
U.S.A.