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<br />GUNNISON AREA, COLORADO
<br />ous in the lower 4 inches. The substratum is st]•ongl}•
<br />calcareous, light-brown loam that extends to a depth of
<br />GO inches.
<br />Evanston soils are at elevations of about 8,000 to
<br />10,000 feet. Summers are cool, alld +ainters are cold.
<br />The average annual soil temperature is ]ass than 95° F.
<br />The average annual precipitation is about ]9 inches.
<br />The native vegetation is commonly Arizona fescue,
<br />mountain muhly, and ncedlegrass. P,ig sagebrush and
<br />rabbitbrush are the principal shrubs.
<br />Permeability is slow. Foots can penetrate to a depth
<br />of GO inches m' more, and available water capacity is
<br />high.
<br />lost of the acreage is used for irrigated native pas-
<br />and Irl}. Small ;u•eas are in native ]:vlge that is
<br />1 ed by both livestock and wildlife.
<br />Typical profile of Evanston loam, 7 to 5 percent
<br />slopes, in a road cut; NE1/9 sec. 7, T. 4G N., R. 3 VJ.,
<br />Gunnison County:
<br />Al-0 to 6 inches, dark-brown (7.6YR 9/2) loam, dark
<br />brown (7.6YR 3/2) moist; moderate, medium, gran-
<br />ular structure; slightly hard, friable; pH 7.0; clear,
<br />wavy boundary.
<br />B1t~G to 9 inches, dark-brown (7.5YR 4/2) loam, dark
<br />brown (7.5YR 3/2) moist; weak, medium, sub-
<br />angular blocky structure parting to moderate, fine,
<br />subangular blocky; hard, friable; thin patchy clay
<br />films on pad faces; pH 7.2; clear, smooth boundary.
<br />B2t~0 to ]4 inches, brown (7.6YR 5/4) clay loam, dnrk
<br />brown (7.5YR 4/4) moist; moderate, coarse, sub-
<br />angular blatky structure parting to moderate, me-
<br />dium to fine, subangular blocky; very hard, firm;
<br />thin continuous clay films on pad faces; pH 7.2;
<br />clear, wavy boundary.
<br />Race-14 to 78 inches, brown (7.5YR 5/4) hexv}• loam, dnrk
<br />brown (7.G1'R 4/4) moist; wank, medium, sub-
<br />angular blocky structure parting to weak, fine, sub-
<br />nngulnr blocky; hard, friable; cnlca rcous; pH 7.8;
<br />gradual, smooth boundary.
<br />Cca-18 to 60 inches -}-, light-brown (7.SYR G/4) loam,
<br />brown (7.5YR 5/4) moist; massive; hard, friable;
<br />5 to ]0 percent rounded and angular cobblestones;
<br />calcareous; calcium carbonate in few fine concre-
<br />tions and in thin scams and streaks; pH 8.4.
<br />The A horizon is typically loam, but in places is gravelly
<br />loam and sandy loam. It ranges from 3 to 10 inches in thick-
<br />ness and from brown to dark brown in color. The B horizon
<br />ranges from brown to Tight brown. Depth to lime ranges
<br />from 12 to 20 inches. The content of gravel and cobblestones
<br />ranges from 0 to 15 percent.
<br />,vanstnn loam, 1 l0 5 percent slopes (E.•BL-This soil
<br />is on alluvial tans and valley-fill slopes, mainly along
<br />Ohio and Tomichi Creeks and their tributaries. It has
<br />the profile described as representative of the series.
<br />included with this soil in mapping are small areas
<br />of Dewville old Curecanti soils and, along Ohio Creek
<br />and the East River, small areas of Fola soils and steep
<br />gravelly terrace edges. Also included are saline spots
<br />and wet areas, which are identified b}• spot symbols
<br />on the soil map. Included soils make up less than 70
<br />percent of the total acreage.
<br />Most of the acreage is irrigated and proriuces good
<br />yields of meadow hay and pasture. Runoff is medium
<br />to slow. The erosion hazard is slight in areas protected
<br />by a plant cover of hay or pasture, but it is moderate
<br />during sno+amelt and in areas where vegetation is
<br />sparse. Capability units Vc-1 irrigated, Vie 2 non-
<br />irrigated; mountain Outw'ash range site.
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<br />Evanston loam, 5 to 20 percent slopes (EvD).-`T'his
<br />soil is ol] alluvial fans and valley sides throughout the
<br />central part of the surve}• area. It is commonly in areas
<br />at Lhe outlets of streams and side drainageways.
<br />Included +vith this soil in mapping are steep cobbly
<br />ten'sce edges and small areas of Dewville and i\lerge]
<br />soils and Alluvial land. included soils make up 15 per-
<br />cent of the total acreage.
<br />!11nst of the acrc:lge is native range and is used for
<br />gratin);. fields of meado+c hay are moderate to good
<br />+vhere irrigation +cater is available. Runoff is medium
<br />to rapid. It accumulates on surrounding soils, concen-
<br />trates in drainageways, and creates gullies. The ero-
<br />sion hazard is moderate. Capability units VIe-1 irri-
<br />gated, \'Ic-2 nunirrigated; Mountain Outwash range
<br />site.
<br />Fola Scricr
<br />The Fula =cries consists of deep, well-drained soils
<br />m] alluvial Luis :Ind terraces. Slopes are 1 to 8 percent.
<br />These soils fm'med in cobbly and sandy alluvium that
<br />was derived from a wide variety of rocks.
<br />in a representative profile the surface layer is brown
<br />cobblt• sandy loam about G inches thick. The subsoil is
<br />reddish-bro+vn very cobbly sandy loam about 10 inches
<br />thick. The substratum to a depth of fi0 inches is brown
<br />very cobbly sandy loam.
<br />Fnla .,oils arc at an elevation about 8,200 feet. The
<br />average annual precipitation is about 14 inches. The
<br />average annual soil temperature is 42° F. The native
<br />vegetation is commonly big sagebrush, western wheat-
<br />grass. Arizona fascuc, anti native bluegrass.
<br />Permeability is rapid. Roots can penetrate to a depth
<br />of GO inches or more, but available water capacity is low.
<br />Fnla soils ;ire important for irrigated hay and pas-
<br />tlll'e.
<br />P,epresi•ntative profile of Fola cobbly sandy loam in
<br />a road cu[ nn the east side of Cement Creek; sec. 27, T.
<br />]4 S., R. 85 11'., Gunnison County:
<br />Al-0 to 6 inches, brown (7.5YR 5/2) cobbly sandy loam,
<br />dark brown (7.5YR 4/2) moist; weak, very fine,
<br />granular structure; soft, very friable; 30 percent
<br />gravel and cobblestones; pH 7~4~ gradual, smooth
<br />boundary.
<br />B?-G to 1G inches, reddish-brown (5YR 5/3) very cobbly
<br />sandy loam, reddish brown (SYR 9/3) moist; moder-
<br />ate, medium, subangular blocky structure; slightly
<br />hard, very friable; small amount of gelatinous coat-
<br />ings on some coarse fragments; 60 percent cobble-
<br />stones and gravel; pH 7.4; gradual, smooth bound-
<br />ary. r
<br />C-16 to 60 inches, brown (7.SYR 5/3) very cobbly sandy
<br />loam, dark brown (7.5YR 9/3) moist; massive;
<br />soft, very friable; 70 percent gravel and cobble-
<br />stones; pH 7.6.
<br />The A horizon is typically cobbly sandy loam, but in
<br />places is sandy loam, stony loam, and loam. IC is 4 to 12
<br />inches thick. The Band C horizons are 35 to 80 percent
<br />gravel and cobblestones.
<br />Fola cobbly sandy loam, 1 to S percent slopes (FoB).-
<br />This soil is on stream terraces and alluvial fans through-
<br />out the suraey area. In some areas it has a thin organic
<br />mat at the surface.
<br />Included +vith this soil in mapping are small areas of
<br />Gateview cobbly loam and Curecanti gravelly loam.
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