LOCATION KETCHUM ID
Established Series
Rev. WDH/MEJ/KLS
08/2022
KETCHUM SERIES
The Ketchum series consists of very deep, well drained soils that formed in colluvium from limestone, quartzitic sandstone and related rock. Ketchum soils are on mountains and have slopes of 20 to 75 percent. Permeability is moderately rapid. The mean annual precipitation is about 510 mm, and the mean annual air temperature is about 3 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Xeric Haplocryepts
TYPICAL PEDON: Ketchum very gravelly loam - on 45 percent north facing slope at an elevation of 2125 meters in timber. When described on October 3, 1978, the soil was slightly moist throughout. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 3 cm; undecomposed forest litter.
Oe--3 to 6 cm; slightly decomposed forest litter. (Combined thickness of O horizons - 0 to 8 cm)
A1--6 to 14 cm; brown (10YR 5/3) very gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine, medium and coarse roots; many very fine irregular pores; 40 percent gravel and 5 percent cobbles; neutral (pH 6.8); abrupt wavy boundary.
A2--14 to 34 cm; pale brown (10YR 6/3) very gravelly fine sandy loam, brown (10YR 4/3) moist; weak fine to medium granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine, medium and coarse roots; many very fine irregular pores; 35 percent gravel and 10 percent cobbles; neutral (pH 6.8); abrupt wavy boundary. (Combined thickness of A horizons - 20 to 45 cm)
Bw1--34 to 87 cm; light gray (10YR 7/2) very gravelly fine sandy loam, yellowish brown (10YR 5/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, medium and coarse roots; common very fine tubular pores; 45 percent gravel and 10 percent cobbles; neutral (pH 7.0); gradual wavy boundary. (18 to 50 cm thick)
Bw2--87 to 112 cm; very pale brown (10YR 7/3), very gravelly sandy loam; brown (10YR 5/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, medium and coarse roots; many very fine and fine tubular pores; 40 percent gravel and 10 percent cobbles; neutral (pH 7.0) clear wavy boundary. (0 to 40 cm thick)
BC--112 to 127 cm; light yellowish brown (10YR 6/4), very gravelly sandy loam; dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, medium and coarse roots; many very fine and fine tubular pores; 50 percent gravel and 5 percent cobbles; neutral (pH 7.0); clear smooth boundary. (15 to 80 cm thick)
C--127 to 160 cm; light gray (10YR 7/2) extremely gravelly coarse sandy loam, brown (10YR 5/3) moist; single grain; loose; many very fine, fine, medium and coarse roots; 75 percent gravel and 10 percent cobbles; neutral (pH 7.0).
TYPE LOCATION: Blaine County, Idaho about 6 km east and 5 km north of Hailey; about 430 meters south and 30 meters west of the northeast corner of sec. 19, T.3 N., R.19 E.; Lat. 43 degrees, 34 minutes, and 45 seconds N; Long. 114 degrees, 13 minutes, and 46 seconds W.
RANGE IN CHARACTERISTICS:
Depth to quartzitic sandstone--more than 150 cm
Mean annual soil temperature--3 to 6 degrees C
Mean summer soil temperature--12 to 15 degrees C
Clay content--10 to 20 percent
Base saturation by ammonium acetate--60 to 75 percent in some subhorizon within a depth of 75 cm
A horizon
Value--4 to 6 dry and 2 to 4 moist
Chroma--2 or 3
Reaction--pH 5.6 to 6.8
Bw horizon
Hue--2.5Y or 10YR
Value--6 to 7 dry and 4 to 5 moist
Chroma--2 to 4
Texture--loam, sandy loam, or fine sandy loam
Rock fragment content--35 to 60 percent
Reaction--pH 6.1 to 7.0
BC horizon
Hue--2.5Y or 10YR
Texture--sandy loam, fine sandy loam, or loam
Rock fragment content--35 to 60 percent
Reaction--pH 6.1 to 7.0
C horizon
Value--6 to 7 dry and 4 to 5 moist
Chroma--2 to 3 moist and dry
Texture--fine sandy loam or loamy coarse sand
Rock fragment content--60 to 80 percent
Reaction--pH 6.1 to 7.8
COMPETING SERIES: These are the
Longhike (T) and
Muiral series. Longhike soils are 75 to 100 cm to a paralithic contact. Muiral soils are moderately deep to bedrock.
GEOGRAPHIC SETTING:
Landform--north and east-facing mountains
Elevation--1825 to 2725 meters
Slope--20 to 75 percent
Parent material--colluvium from limestone, quartzitic sandstone and related rock
Mean annual precipitation--460 to 610 mm, most of which falls as snow and early spring rains
Mean annual air temperature--2 to 4 degrees C
Frost-free season--less than 60 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed
DRAINAGE AND PERMEABILITY: Well drained; rapid to very rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Mainly used for range and timber. Vegetation is Douglas-fir with an understory of mountain snowberry, pine reedgrass, elk sedge and ninebark.
DISTRIBUTION AND EXTENT: Ketchum soils are extensive in southcentral Idaho; MLRAs 12 and 43B
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Blaine County, Idaho, 1985
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon-6 to 34 cm (A1 and A2 horizons)
Cambic horizon--34 to 112 cm (Bw1 and Bw2 horizons)
Particle-size control section--25 to 100 cm (part of the A2 horizon, all of the Bw1 horizon, and part of the Bw2 horizon)
Ketchum soils have a cryic temperature regime and a xeric soil moisture regime.
The 3/2008 description reflects a change in classification from Loamy-skeletal, mixed, superactive Xeric Eutrocryepts to Loamy-skeletal, mixed, superactive Xeric Haplocryepts due to revision of the cryepts great groups and subgroups. The competing series section was not updated and should be reviewed after all the cryepts have been re-classified.
Converted to metric, updated formatting, and O horizons were updated to start at zero. 8/2022
National Cooperative Soil Survey
U.S.A.