LOCATION KIMBALLPASS             AK

Tentative Series
SDB
08/2025

KIMBALLPASS SERIES

Depth class: very deep
Drainage class: well drained
Parent material: grassy organic material over gravelly colluvium
Landscape: mountains
Landform: mountain slopes
Slope: 20 to 70 percent
Mean annual precipitation: about 600 mm (24 in)
Mean annual air temperature: about 2 degrees C (36 degrees F)
Frost-free period: 40 to 103 days

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, nonacid, subgelic Typic Haplogelolls

TYPICAL PEDON: Kimballpass gravelly silt loam in a dryas community on a south facing convex, linear backslope on a slope of 42 percent at an elevation of 1348m (4425 ft)

Oe--0 to 9 cm (0 to 4 in); moderately decomposed plant material, very dark brown (10YR 2/2) broken face moist; low excavation difficulty; many very fine, common fine and medium roots throughout; noneffervescent; slightly alkaline (pH 7.4); clear smooth boundary

A--9 to 30 cm (4 to 12 in); very gravelly silt loam, very dark brown (10YR 2/2) broken face moist; weak fine granular structure; soft, very friable, nonsticky, nonplastic; nonsmeary; many very fine, common fine, and medium roots throughout; many very fine and fine dendritic tubular pores; 3 percent subangular cobbles by volume, 30 percent angular gravel by volume; slightly acid (pH 6.4); clear wavy boundary

C--30 to 150 cm (12 to 59 in); extremely gravelly loam, dark brown (10YR 3/3) broken face moist; massive; soft, very friable, nonsticky, nonplastic; nonsmeary; common very fine and fine roots throughout; common very fine and fine dendritic tubular pores 5 percent subangular cobbles by volume, 65 percent angular gravels by volume; slightly acid (pH 6.4).

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; latitude 61.65707, longitude -145.26965, UTM 6837196.17 north and UTM 591640.43 east, zone 6, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: udic
Soil temperature regime: cryic
Mean annual soil temperature: 0 to 5 degrees C. (32 to 41 degrees F)
Thickness of organic material: 6 to 12 cm (3 to 5 in)
Thickness of mollic epipedon: 18 to 30 cm (7 to 12 in)

Oi, Oe, Oa horizons:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 3
Texture: slightly decomposed organic material, moderately decomposed organic material, and highly decomposed organic material.
Organic matter: 60 to 90 percent
Reaction class: neutral to moderately alkaline (pH 7 to 8)

A horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 2 to 3
Texture: silt loam, gravelly silt loam, very gravelly silt loam
Sand: 25 to 45 percent
Silt: 50 to 70 percent
Clay: 5 to 15 percent
Rock fragments: 7 to 44 percent
Gravels: 5 to 40 percent
Cobbles: 2 to 6 percent
Organic matter: 2.5 to 7 percent
Reaction class: moderately acid to neutral (pH 5.6 to 6.8)

C horizon:
Hue: 10YR or 2.5Y
Value: 3 to 4
Chroma: 2 to 3
Texture: extremely gravelly loam
Sand: 35 to 50 percent
Silt: 37 to 50 percent
Clay: 8 to 15 percent
Rock fragments: 65 to 75 percent
Gravels: 62 to 68 percent
Cobbles: 3 to 7 percent
Organic matter: 1 to 3 percent
Reaction class: moderately acid to neutral (pH 5.6 to 6.8)

COMPETING SERIES: This is the Kulik (AK) series which has a lithic contact between 50 and 100 cm (20 to 39 in).

GEOGRAPHIC SETTING:
Elevation: 600 to 1400 meters (1969 to 4593 ft)
Parent material: grassy organic material over gravelly colluvium
Landform: mountain slopes
Slopes: 20 to 70 percent
Mean annual precipitation: 300 to 1400 mm (12 to 55 in)
Mean annual air temperature: 0 to 5 degrees C. (32 to 41 degrees F)
Frost-free period: 40 to 103 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bernardpeak, Cirquecreek, Fourthofjuly, Greylingcreek, Ride,and Swampylakes soils.
Bernardpeak soils are somewhat poorly drained, are organic soils, and occur on stream terraces in mountain valleys.
Cirquecreek soils are well drained, do not have a mollic epipedon, and occur on saddles and mountain slopes
Fourthofjuly soils are well drained, have folistic epipedons, and occur on mountain valleys and stream terraces.
Greylingcreek soils are excessively drained, do not have a mollic epipedon, and occur in mountain valleys and moraines.
Ride soils are somewhat excessively drained, with very gravelly sandy loam surface textures, and occur on mountain slopes and hillslopes.
Swampylakes soils are somewhat poorly drained, a mollic epipedon, aquic conditions starting between 34 and 40 cm (13 and 16in), on mountain slopes and hillslopes.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well drained
Saturated Hydraulic Conductivity: very high in the Oe horizon, high in the C horizon, and moderately high in the A horizon
Permeability: very rapid in the Oe horizon, moderately rapid in the C horizon, and moderate in the A horizon.
Runoff: high

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: Dryas and willow

DISTRIBUTION AND EXTENT: MLRA 228 Interior Alaska mountains.
Extent: moderate

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Wasilla, Alaska

SERIES ESTABLISHED: North Copper River Soil Survey, Alaska, 2024.

REMARKS: Diagnostic features and horizons recognized in this profile include:

Particle-size control section: 34 to 109 cm (13 to 43 in)

mollic epipedon: 9 to 30 cm (4 to 12 in) (A horizon)

ADDITIONAL DATA:

User pedon Id: 2022AK261568

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National Cooperative Soil Survey
U.S.A.