LOCATION REDPEAK WA
Established Series
Rev. BJD/TDT
01/2011
REDPEAK SERIES
The Redpeak series consists of moderately deep, well drained soils formed in residuum, colluvium and some till from sedimentary and volcanic rock sources of the Ventura Member of the Midnight Peak Formation, with a component of volcanic ash in the upper part. These soils are on backslopes and shoulders of mountains. Slopes are 35 to 65 percent. The average annual precipitation is about 22 inches, and the average annual temperature is about 43 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Vitrandic Haploxerepts
TYPICAL PEDON: Redpeak gravelly ashy sandy loam, on a northeast facing 60 percent slope at an elevation of 2,800 feet in a Douglas-fir and ponderosa pine forest. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures.)
Oe-- 0 to 1 inch; moderately decomposed needles and twigs; abrupt smooth boundary. (1 to 3 inches thick)
A--1 to 5 inches; reddish brown (5YR 4/3) gravelly ashy sandy loam, dark reddish brown (5YR 3/3) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and few medium and coarse roots; common very fine and fine irregular pores; 15 percent pebbles; slightly acid (pH 6.5); clear wavy boundary. (4 to 8 inches thick)
Bw1--5 to 10 inches; reddish brown (2.5YR 5/3) gravelly ashy sandy loam, reddish brown (2.5YR 4/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and few medium and coarse roots; common fine and very fine irregular pores; 20 percent pebbles; slightly acid (pH 6.4); clear wavy boundary.
Bw2--10 to 17 inches; reddish brown (2.5YR 5/3) very gravelly ashy sandy loam, dark reddish brown (2.5YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine, and few medium roots; common fine and very fine irregular pores; 30 percent pebbles and 5 percent cobbles; neutral (pH 6.6); clear wavy boundary. (combined Bw horizon thickness is 6 to 12 inches)
2C1--17 to 29 inches; reddish brown (2.5YR 4/3) very gravelly sandy loam, dark reddish brown (2.5YR 3/3) moist; massive; soft, very friable, slightly sticky and nonplastic; common very fine and fine roots; few fine irregular pores; 40 percent pebbles and 5 percent cobbles; neutral (pH 6.6); clear wavy boundary.
2C2--29 to 36 inches; reddish brown (2.5YR 4/3) very gravelly sandy loam, dark reddish brown (2.5YR 3/3) moist; massive; soft, very friable, slightly sticky and nonplastic; few very fine and fine roots; few fine irregular pores; 50 percent pebbles and 5 percent cobbles;slightly acid (pH 6.4); adrupt irregular boundary. (Combined thickness if the 2C horizon is 10 to 20 inches thick).
2R--36 inches; red sandstone
TYPE LOCATION: Okanogan County, Washington; about 1.5 miles southwest of Mazama, Wa., 1,500 feet west and 1,200 feet north of the southeast corner of section 36, T. 36 N., R. 19 E. (Latitude 48 degrees 34' 30"N., Longitude 120 degrees 24' 27"W.)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 42 to 46 degrees F. These soils are usually moist but are dry in all parts of the moisture control section for 60 to 75 days following the summer solstice. Depth to bedrock ranges from 20 to 40 inches. These soils do not meet the organic-carbon content of 0.6 or more for mollic epipedons. Thickness of the volcanic ash influence is 10 to 20 inches, and has an estimated moist bulk density of 1.10 to 1.40 g/cc, volcanic glass content of 5 to 20 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 0.4 to 1.0 percent, and 15-bar water retention of 5 to 10 percent for air dried samples. The particle-size control section averages 35 to 60 percent rock fragments and 10 to 20 percent clay. Reaction is slightly acid to neutral throughout.
The A horizon has hues of 2.5YR and 5YR, and chromas of 2 or 3 dry or moist.
The Bw horizon has hues of 2.5YR and 5YR, and values of 3 or 4 moist. It is gravelly ashy sandy loam, gravelly ashy loam or very gravelly ashy sandy loam. It has 15 to 30 percent pebbles and 0 to 5 percent cobbles.
The 2C horizon has hues of 2.5YR and 5YR, values of 4 or 5 dry, 3 or 4 moist, and chromas of 2 or 3 dry or moist. It is very gravelly sandy loam or very gravelly loam. It has 30 to 50 percent pebbles and 0 to 10 percent cobbles.
COMPETING SERIES: These are the
Brevco,
Coxit,
Elkrock,
Highhorn,
Huntrock,
Jimbluff,
Kamela,
Longort,
Merkel,
Ontrail, and
Thout series. Brevco soils have coarse sandy loam textures in the C horizon and Thout soils lack a C horizon. Coxit,
Elkhorn, Jimbluff, Longort, Ontrail and Merkel soils are very deep. Highhorn soils have 27 to 35 percent clay in the particle-size control section and are 40 to 60 inches to bedrock. Huntrock soils have 27 to 35 percent clay and 60 to 80 percent rock fragments in the particle-size control section. Kamela have a Bw horizon with 18 to 27 percent clay.
GEOGRAPHIC SETTING: Redpeak soils are on backslopes and shoulders of mountains. Elevations range from 2,200 to 3,800 feet. Slopes are 35 to 65 percent. These soils formed in residuum, colluvium and some till from sedimentary and volcanic rock sources of the Ventura Member of the Midnight Peak Formation, with a component of volcanic ash in the upper part. The climate is characterized by warm, dry summers and cool, moist winters. The average annual precipitation ranges from 20 to 24 inches. The average January temperature ranges from 22 to 26 degrees F.; the average July temperature ranges from 62 to 67 degrees F.; and the average annual air temperature ranges from 40 to 44 degrees F. The frost-free season is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buckrock,
Jimbluff,
Ontrail, and
Veridge soils. Buckrock soils are on open shoulders and ridges and are mesic. Jimbluff soils are on footslopes and alluvial fans. Ontrail soils are on backslopes and are very deep. Veridge soils are on northerly aspects and have an andic volcanic ash mantle 7 to 14 inches thick.
DRAINAGE AND PERMEABILITY: Well drained, very rapid runoff; moderate permeability.
USE AND VEGETATION: Used for timber production, wildlife habitat, watershed, recreation, and livestock grazing. Native vegetation is Douglas fir and ponderosa pine, with an understory of pinegrass, shinyleaf spirea, Saskatoon serviceberry and mountain snowberry.
DISTRIBUTION AND EXTENT: Northcentral Washington. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Okanogan National Forest, Okanogan County, Washington, 2005.
REMARKS: Diagnostic horizons and features in this pedon include: Ochric epipedon - 0 to 4 inches (A horizon)
Cambic horizon - 4 to 16 inches (Bw horizon)
Lithic contact - 35 inches (R horizon)
PSCS - zone from 10 to 35 inches (Bw2, 2C1 and 2C2 horizon)
Vitrandic properties from 0 to 16 inches.
National Cooperative Soil Survey
U.S.A.