LOCATION FOURTHOFJULY AK

Established Series
SDB
08/2025

FOURTHOFJULY SERIES

Depth class: very deep
Drainage class: well drained
Parent material: organic material over till
Landscape: mountains
Landform: mountain valleys, stream terraces
Slope: 5 to 35 percent
Mean annual precipitation: about 600 mm (24 in)
Mean annual air temperature: about -1.5 degrees C (29 degrees F)
Frost-free period: 40 to 103 days

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Typic Haplocryepts

TYPICAL PEDON: Fourthofjuly peat in a shrub birch community on a south-eastern facing linear, convex backslope on a slope of 6 percent at an elevation of 920m (3020 ft)

Oi--0 to 19 cm (0 to 7 in); slightly decomposed plant material, very dark brown (10YR 2/2) moist; many very fine, and common fine and coarse roots throughout; strongly acid (pH 5.3); abrupt wavy boundary (4 to 19 cm, 2 to 7 in)

A/E--19 to 30 cm (7 to 12 in); loam, 80 percent very dark brown (10YR 2/2) broken face and 20 percent pale brown (10YR 6/3) broken face moist; weak medium granular structure; slightly hard, friable, nonsticky, nonplastic; nonsmeary; many very fine roots throughout; common very fine tubular pores; slightly acid (pH 6.1); clear wavy boundary. (3 to 15 cm, 1 to 6 in)

Bw--30 to 51 cm (11.8 to 20.1 in); sandy loam, yellowish brown (10YR 5/6) broken face moist; weak medium subangular blocky parts to weak medium granular structure; soft, very friable, nonsticky, nonplastic; nonsmeary; common very fine roots throughout; 8 percent subrounded gravel by volume; slightly acid (pH 6.5); abrupt wavy boundary. (13 to 36 cm, 5 to 14 in)

C--51 to 200 cm (20.1 to 78.7 in); gravelly sandy loam, olive (5Y 5/3) broken face moist; single grain; soft, very friable, nonsticky, nonplastic; nonsmeary; common very fine roots throughout; 13 percent subrounded gravel by volume; neutral (pH 6.6) (84 to 130cm, 33 to 51 in)

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; latitude 61.54924, longitude -145.07275, UTM 6825481.99 north, and UTM 602421.59 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: 4 to 19 cm (2 to 6 in)
Thickness of ochric or folistic epipedon: 7 to 34 cm (3 to 7 in)
Thickness of cambic horizon: 15 to 36 cm (6 to 14 in)

Oi, Oe, or 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: strongly acid to slightly acid (pH 5.1 to 6.5)

A and A/E horizon:
A Hue: 10YR or 2.5Y
A Value: 2 to 3
A Chroma: 1 to 3
E Hue: 10YR or 2.5Y
E Value: 5 to 6
E Chroma: 1 to 3
Texture: loam or silt loam
Sand: 25 to 50 percent
Silt: 36 to 61 percent
Clay: 5 to 14 percent
Rock fragments: 0 to 14 percent
Gravels: 0 to 14 percent
Organic matter: 1 to 5.2 percent
Reaction class: slightly acid to neutral (pH 6.1 to 7.3)

Bw horizon:
Hue: 10YR or 2.5Y
Value: 3 to 5
Chroma: 3 to 6
Texture: sandy loam, loam, gravelly loam, gravelly sandy loam
Sand: 40 to 75 percent
Silt: 10 to 46 percent
Clay: 7 to 15 percent
Rock fragments: 5 to 28 percent gravels
Organic matter: 0.5 to 2.0 percent
Reaction class: slightly acid to neutral (pH 6.1 to 7.3)

C horizon:
Hue: 2.5Y or 5Y
Value: 4 to 5
Chroma: 3 to 4
Texture: sandy loam, loam, gravelly loam, gravelly sandy loam
Sand: 40 to 75 percent
Silt: 10 to 45 percent
Clay: 10 to 15 percent
Rock fragments: 5 to 26 percent gravels
Organic matter: 0.1 to 1.0 percent
Reaction class: slightly acid to neutral (pH 6.1 to 7.3)

COMPETING SERIES: These are the Eska (AK), Ganhona (AK), Kaknau (AK), Kalambach (AK), Progress (AK), Southpaw (AK), Steese (AK), Tebay (AK), Tsana (AK), and Uranatina (AK) soils
Eska soils are somewhat poorly drained, have a loess mantle, and occur on till plains and hills.
Ganhona soils lack gravelly substratums, and occur on river valleys, flood plains, and lacustrine terraces in mountains.
Kaknau soils have a paralithic contact within 2 m (79 in) of surface and occur on glacially modified hillslopes.
Kalambach soils have a lithic discontinuity between 20 and 94 cm (8 and 37 inches) and occur on till plains and hills.
Progress soils lack coarse fragments in its lower horizons, the parent material soils are loess over alluvium or deposits reworked by wind, and occur on stream terraces, plains and hills.
Southpaw soils have 40 to 70 percent gravel in glacial till substratum and occur on glacial hills.
Steese soils have a paralithic contact within 2 meters of the soil surface and occur on mountains and hills.
Tebay soils occur on drumlins, moraines, and undulating till plains at elevations less than 671 m (2200 ft).
Tsana soils lack mottles in the substratum and occur on till plains.
Uranatina soils have a cobbly silt loam texture in all mineral horizons and occur on outwash plains.

GEOGRAPHIC SETTING:
Elevation: 600 to 1400 meters (1970 to 4595 ft)
Parent material: organic material over till
Landform: mountain valleys, stream terraces
Slopes: 5 to 35 percent
Mean annual precipitation: 300 to 1400 mm (12 to 55 in)
Mean annual air temperature: -5 to 1 degrees C. (23 to 34 degrees F)
Frost-free period: 40 to 103 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alterationcreek, Bernardpeak, Cirquecreek, Greylingcreek, Haleycreek, and Hanagita soils.
Alterationcreek soils have bedrock at a within 200 cm (79 in) and occur on hillslopes and mountain valleys.
Bernardpeak soils are somewhat poorly drained, are organic soils, and occur on stream terraces in mountain valleys.
Cirquecreek soils have family texture class of loamy skeletal and occur on saddles and mountain slopes.
Greylingcreek soils are excessively drained, have family texture class of sandy-skeletal, and occur in mountain valleys and moraines.
Haleycreek soils have a mollic epipedon and occur on hillslopes of mountains and river valleys.
Hanagita soils have a mollic epipedon, are moderately deep to bedrock, and occur on hills in loess and till covered bedrock.

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

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: resin birch, crowberry, lichen

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: 44 to 119 cm (17 to 47 in)

Folistic epipedon: 0 to 19 cm (0 to 7 in) (Oi horizon)

Cambic Horizon: 30 to 51 cm (12 to 20 in) (Bw horizon)

ADDITIONAL DATA:

User pedon Id: 2022AK261327

National Cooperative Soil Survey
U.S.A.