LOCATION WASHOUGAL WAEstablished Series
TAXONOMIC CLASS: Medial, amorphic, mesic Pachic Melanoxerands
TYPICAL PEDON: Washougal loam - forested. (Colors are for moist soil unless otherwise noted.)
O1--1 inch to 0; leaves, needles, twigs and grasses.
A1--0 to 5 inches; black (10YR 2/1) loam, very dark grayish brown (10YR 3/2) dry; moderate very fine and medium granular structure; soft, very friable, nonsticky, slightly plastic and weakly smeary; many fine roots; many fine irregular pores; very strongly acid (pH 5.0); clear smooth boundary. (4 to 6 inches thick)
A2--5 to 14 inches; black (10YR 2/1) gravelly loam, very dark grayish brown (10YR 3/2) dry; weak fine and medium granular structure; soft, very friable, nonsticky, nonplastic and weakly smeary; common fine roots; common very fine and fine irregular pores; 20 percent pebbles; very strongly acid (pH 5.0); gradual smooth boundary. (8 to 12 inches thick)
A3--14 to 22 inches; very dark brown (10YR 2/2) gravelly loam, dark grayish brown (10YR 4/2) dry; weak coarse subangular blocky structure; soft, very friable, nonsticky, nonplastic and weakly smeary; common very fine roots; common medium irregular pores; 20 percent pebbles; strongly acid (pH 5.1); abrupt irregular boundary. (6 to 12 inches thick)
AC--22 to 30 inches; dark brown (7.5YR 3/2) very gravelly loam, brown (7.5YR 4/2) dry; massive; soft, very friable, nonsticky, nonplastic; common very fine and few medium roots; many fine and medium irregular and few fine tubular pores; 30 percent pebbles and 15 percent cobbles; strongly acid (pH 5.2); abrupt irregular boundary. (6 to 12 inches thick)
C1--30 to 36 inches; dark brown (10YR 3/4) extremely gravelly coarse sandy loam, brown (10YR 5/3) dry; massive; slightly hard, friable, nonsticky, slightly plastic; few very fine roots; common fine and medium irregular pores; 50 percent pebbles and 25 percent cobbles; intermittent weak silica and manganese cementation; strongly acid (pH 5.2); abrupt irregular boundary. (4 to 12 inches thick)
2C2--36 to 60 inches; dark brown (7.5YR 3/3) extremely cobbly coarse sand, brown (7.5YR 5/3) dry; single grain; loose; many medium and coarse irregular pores; 35 percent pebbles, 20 percent cobbles and 10 percent stones; strongly acid (pH 5.1).
TYPE LOCATION: Skamania County, Washington; near Clark County line, 600 feet northeast of the steel bridge on Shields Skye Road, 900 feet north and 300 feet west of the southeast corner of sec. 31, T. 2 N., R. 5 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 49 to 51 F. Solumn thickness and depth to 2C horizon ranges from 24 to 40 inches. The umbric epipedon is 20 to 30 inches thick.
The A and AC horizon has value of 2 or 3 moist, 3 or 4 dry and chroma of 1 or 2 moist and dry. Coarse fragments range from 0 to 25 percent in the A horizon and 35 to 60 percent in the AC horizon. The A and AC horizons are very strongly acid or slightly acid.
The C horizon as hue of 10YR or 7.5YR, value of 3 or 4 moist, 4 through 6 dry and chroma of 2 through 4 moist and dry. It is very gravelly coarse sandy loam, very cobbly coarse sandy loam, extremely cobbly coarse sandy loam or extremely gravelly loamy sand.
The 2C horizon has hue of 7.5YR or 10YR, value of 3 or 4 moist, 4 through 6 dry, and chroma of 2 through 4 moist and dry. Pebbles range from 20 to 50 percent, cobbles from 15 to 25 percent and stones from 0 to 10 percent. This horizon is loam, sandy loam, loamy sand or coarse sand, and is very gravelly, very cobbly or extremely cobbly.
COMPETING SERIES: kThis is the Mossyrock series. Lauren soils are dry for 60 to 75 consecutive days and have a cambic horizon. Spana soils have rock fragments dominately of glacial till origin, and have a cambic horizon. Mossyrock soils have a solum greater than 60 inches and lack sandy-skeletal 2C horizons at depths of 24 to 40 inches.
GEOGRAPHIC SETTING: Washougal soils are on river terraces and terrace escarpments. The soil formed in mixed gravelly alluvium from volcanic ash, basalt and andesite. Washougal soils are at elevations of 50 to 800 feet and have slopes of 0 to 60 percent. Climate is mild; with warm, dry summers and cool, wet winters. The annual precipitation is 50 to 90 inches. Average January temperature is 32 F, average July temperature is 64 F, and the mean annual temperature is 47 to 50 F. Frost-free season ranges from 150 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gee, Kinney, Hesson, Odne, Olyic and Skoly soils. Gee soils are fine-silty. Kinney, Hesson and Olyic soils are non-skeletal. Odne soils have an aquic moisture regime and are fine-silty. Skoly soils have a udic moisture regime.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow or very slow runoff; moderate permeability in the solum and very rapid in the substratum. It is subject to rare flooding but in some areas is not subject to flooding.
USE AND VEGETATION: Used for timber production, pasture, recreation, wildlife habitat, homesites and cropland. Small grains and hay are principal crops. Native vegetation is Douglas-fir, red alder, grand fir, and bigleaf maple with an understory of vine maple hazel, Oregon-grape, and grasses.
DISTRIBUTION AND EXTENT: Southwestern Washington. The soil is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skamania County, Washington, 1947.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy.
Diagnostic horizons and features recognized in this pedon include:
Andic properties - from 0 to 30 inches
Melanic epipedon 0 from 0 to 30 inches with assumed weighted average organic carbon content of more than 6 percent
Particle-size control section - from 0 to 40 inches with 0 to 22 inches being medial; 22 to 30 inches being medial-skeletal; 30 to 36 inches being loamy-skeletal; and 36 to 40 inches being sandy-skeletal. The particle-size class is based on the thickest part between 0 and 40 inches since there are no qualifying strongly contrasting layers.
More investigation is needed to determine whether the organic carbon meets the criteria for a melanic epipedon.