LOCATION TOK                     AK

Established Series
SDB/MJS
08/2025

TOK SERIES

Depth class: very deep
Drainage class: well drained
Parent material: organic material over till
Landscape: till plains, mountains
Landform: kames, glacial-valley floors
Slope: 1 to 40 percent
Mean annual precipitation: about 600 mm (24 in)
Mean annual air temperature: about -3 degrees C (27 degrees F)
Frost-free period: 36 to 71 days

TAXONOMIC CLASS: Sandy-skeletal, mixed Typic Haplocryepts

TYPICAL PEDON: Tok loam in a bog labrador tea and black spruce community on an east facing shoulder slope on a slope of 6 percent at an elevation of 816m (2675 ft).

Oi--0 to 7 cm (0 to 3 in); slightly decomposed plant material, dark brown (7.5YR 3/2) dry, very dark brown (7.5YR 2.5/2) moist; many very fine, few fine, common medium, and many coarse roots throughout; extremely acid (pH 4.3); abrupt wavy boundary (5 to 10 cm, 2 to 4 in)

A--7 to 12 cm (3 to 5 in); loam, black (10YR 2/1) moist; weak fine granular structure; soft, very friable, nonsticky, nonplastic; nonsmeary; many very fine and common fine roots throughout; very fine and fine dendritic tubular pores; very strongly acid (pH 4.5); clear wavy boundary (5 to 11 cm, 2 to 4 in)

Bw--12 to 34 cm (5 to 13 in); fine sandy loam, dark yellowish brown (10YR 3/4) moist; weak medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common very fine and fine roots throughout; very fine and fine dendritic tubular pores; very strongly acid (pH 5.0); abrupt wavy boundary (15 to 28 cm, 6 to 11 in)

C--34 to 150 cm (13 to 59 in); extremely gravelly loamy sand, dark olive brown (2.5Y 3/3) moist; single grain; loose, nonsticky, nonplastic; nonsmeary; few very fine and fine roots throughout; interstitial pores; 65 percent gravel by volume; strongly acid (pH 5.4); clear wavy boundary. (101 to 125 cm, 40 to 49 in)

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; latitude 62.91521, longitude -143.66121, UTM 6978937.56 north and UTM 364840.76 east, zone 7, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: udic
Soil temperature regime: cryic
Mean annual soil temperature: -1 to 5 degrees C. (30 to 41 degrees F)
Thickness of organic material: 5 to 10 cm (2 to 4 in)
Thickness of ochric epipedon: 10 to 21 cm (4 to 8 in)
Thickness of cambic horizon: 15 to 28 cm (6 to 11 in)

Oi, Oe, Oa horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 3
Texture: slightly decomposed organic material, moderately decomposed organic material, highly decomposed organic material.
Organic matter: 60 to 90 percent
Reaction class: extremely acid to very strongly acid (pH 3.5 to 4.5)

A horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 3
Texture: loam
Sand: 37 to 51 percent
Silt: 34 to 50 percent
Clay: 8 to 16 percent
Rock fragments: 0 percent
Organic matter: 4 to 13 percent
Reaction class: extremely acid to very strongly acid (pH 4.4 to 5.0)

Bw horizon:
Hue: 10YR or 2.5Y
Value: 3 to 5
Chroma: 3 to 6
Texture: fine sandy loam
Sand: 55 to 75 percent
Silt: 9 to 40 percent
Clay: 5 to 16 percent
Rock fragments: 0 percent
Organic matter: 1 to 5 percent
Reaction class: very strongly acid to strongly acid (pH 4.5 to 5.1)

C1, C2 horizon:
Hue: 10YR or 2.5Y
Value: 3 to 5
Chroma: 2 to 3
Texture: gravelly loamy sand
Sand: 75 to 86 percent
Silt: 9 to 22 percent
Clay: 2 to 5 percent
Rock fragments: 55 to 75 percent gravel
Organic matter: 0.1 to 1 percent
Reaction class: strongly acid (pH 5.1 to 5.1)

COMPETING SERIES: These are the Como, Donnelly, Pagga, Pippin, Sinona, Southriver, and Tisa soils.
Como soils have a sandy surface layer
Donnelly soils are formed from micaceous loess
Pagga soils have an E horizon and a lithic contact between 1 and 2 m (39 and 79 cm)
Pippin soils have a higher pH in their mineral layers and effervesce.
Sinona and Southriver soils lack silty loess mantles.
Tisa soils lack an A horizon and lack a loess cap.

GEOGRAPHIC SETTING:
Elevation: 500 to 1200 meters (1640 to 3935 ft)
Parent material: organic material over till
Landform: kames, glacial-valley floors
Slopes: 1 to 40 percent
Mean annual precipitation: 400 to 800 mm (16 to 31 in)
Mean annual air temperature: -4 to -2 degrees C. (25 to 28 degrees F)
Frost-free period: 36 to 71 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dodger, Drashner, Fields, Greylingcreek, Hungryhollow, Mahloriver, Manker, and Tsina soils.
Dodger soils are organic soils, have permafrost, and occur on outwash terraces on mountains.
Drashner soils are somewhat poorly drained, have a histic epipedon, and occur on mountains and hillslopes.
Fields soils have mollic epipedons, a lithic contact within 2 m (79 in), and occur on hillslopes and mountain slopes.
Greylingcreek soils are excessively drained, have extremely stony parent material, and occur in mountain valleys and moraines.
Hungryhollow soils are poorly drained, have permafrost, have mineral soil starting between 52 and 73 cm (21 and 29 in) deep, and occur in mountain valleys.
Mahloriver soils are well drained, have till and slope alluvium as parent material, and occur on kames and glacial valley floors.
Manker soils are permafrost soils, it has a cryoturbated horizon, lack a lithic contact, and occur on north facing slopes
Tsina soils lack a cambic horizon and occur on mountain slopes above 800 m (2600ft) elevation.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well drained
Saturated Hydraulic Conductivity: Very high in the Oi and C horizons, high in the A and Bw horizons.
Permeability: Very rapid in the Oi and C horizons, moderately rapid in the A and Bw horizons.
Runoff: low

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: bog labrador tea, black spruce, moss

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: 32 to 107 cm (13 to 42 in)

Ochric epipedon: 0 to 12 cm (0 to 5 in) (Oi and A horizons)

Cambic horizon: 12 to 34 cm (5 to 13 in) (Bw horizon)

ADDITIONAL DATA:

User pedon Id: 2023AK261511

---

National Cooperative Soil Survey
U.S.A.