LOCATION JEFFLAKE                WY+MT

Tentative Series
JH/AB/KLS
11/2022

JEFFLAKE SERIES

The Jefflake series consists of deep, somewhat poorly drained soils formed in glacial till which overlies soft sediments of Quaternary and Tertiary Age. These soils are on nearly level to moderately steep mountain slopes, ridges, plateaus, and basins. Slopes are both simple or complex and are 0 to 25 percent. The mean annual precipitation is about 890 mm, and the mean annual air temperature is about 4 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic Aquic Haplocryalfs

TYPICAL PEDON: Jefflake very gravelly sandy clay loam-timber. (Colors are for dry soil unless otherwise stated)

Oi--0 to 3 cm; partially decomposed litter of conifer needles and twigs.

E--3 to 26 cm; light gray (10YR 7/2) very gravelly sandy clay loam, pale brown (10YR 6/3) moist; weak medium subangular blocky structure; soft, friable, slightly sticky and nonplastic; common fine and medium roots and few coarse roots; common fine and medium interstitial pores and few medium tubular pores; 40 percent pebbles and 5 percent cobbles; very strongly acid (pH 5.0); clear wavy boundary. (15 to 28 cm thick)

Bt1--26 to 56 cm; brownish yellow (10YR 6/6) very gravelly heavy clay loam, yellowish brown (10YR 5/6) moist; few fine distinct grayish brown (10YR 5/2) mottles, moderate medium and fine subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common fine and medium roots and few coarse roots; common fine and medium interstitial pores and few medium tubular pores; common thin clay films on faces of peds and lining pores; 35 percent pebbles and 5 percent cobbles; strongly acid (pH 5.4); clear smooth boundary.

Bt2--56 to 112 cm; reddish yellow (7.5YR 6/6) very gravelly clay, strong brown (7.5YR 5/8) moist; few fine distinct grayish brown (10YR 5/2) mottles; moderate medium and fine subangular blocky structure; very hard, very firm, very sticky and plastic; few fine and medium roots; few fine interstitial pores; many thin clay films on faces of peds, common moderately thick clay films lining pores; 30 percent pebbles and 10 percent cobbles; moderately acid (pH 5.6); gradual wavy boundary. (Combined thickness of the Bt horizons - 50 to more than 150 cm)

BCg--112 to 155 cm; brownish yellow (10YR 6/6) very gravelly clay loam, brownish yellow (10YR 6/6) moist; few fine distinct grayish brown (10YR 5/2) and black (10YR 2/1) mottles; weak fine subangular blocky structure; very hard, very firm, very sticky and plastic; few fine roots; few fine interstitial pores; few thin clay films on faces of peds; 30 percent pebbles and 15 percent cobbles; moderately acid (pH 5.8).

TYPE LOCATION: Albany County, Wyoming; NE1/4, SW1/4 of sec. 10, T. 16 N., R. 78 W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--6 to 8 degrees C
Mean summer temperature--8 to 12 degrees C
Depth to base of argillic horizon--75 to 150 cm or more
Some or all parts of the argillic horizon contain low chroma mottles of 2 or 1 within 75 cm of the surface

E horizon
Hue--6 or 7 dry, 4 through 6 moist
Chroma--1 through 3
Rock fragment content--35 to 60 percent pebbles or cobbles or a mixture of each
Reaction--pH 4.5 to 6.0

Bt horizon
Hue--5YR through 5Y
Value--4 through 6 dry, 2 through 5 moist
Chroma--3 through 8
Texture--clay, clay loam, or sandy clay loam
Clay content--35 to 50 percent
Rock fragment content--35 to 60 percent pebbles, cobbles, or a mixture of each
Low chroma mottles are common and some horizons are gleyed throughout
Reaction--pH 5.1 to 6.5

COMPETING SERIES: There are no other soils in this class. The Potlatch soils are similar but lack the skeletal control section.

GEOGRAPHIC SETTING:
Landform--mountain slopes, plateaus, ridges, and basins
Elevation--2825 to 3050 meters
Slope--0 to 25 percent
Parent material--glacial till
Mean annual precipitation--640 to 1000 mm
Mean annual air temperature--3 to 7 degrees C
Frost-free period--less than 60 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow or medium runoff; moderately slow permeability

USE AND VEGETATION: Timber and wildlife habitat. Native vegetation consists of subalpine fir, Englemann spruce, lodgepole pine, bluejoint reedgrass, and elk sedge.

DISTRIBUTION AND EXTENT: Jefflake soils are moderately extensive in the mountainous regions of western and central Montana and southcentral Wyoming. MLRAs 43A and 43B

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

SERIES PROPOSED: Medicine Bow National Forest, Central Part, Albany and Carbon Counties, Wyoming; 1984

Classification corrected to Alfisol and superactive by the Lakewood office and references to the Slumpy series were removed. 7/97

Converted to metric, updated formatting, and O horizons were updated to start at zero. Competing series section was not updated. 11/2022

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National Cooperative Soil Survey
U.S.A.