LOCATION PLAYCO WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic Andic Haplocryods
TYPICAL PEDON: Playco ashy loamy sand - forested on a 55 percent north slope at 3,350 feet. (color is for moist soil unless otherwise stated. All textures are apparent field textures.)
Oi--0 to 0.5 inch; slightly decomposed loose forest litter, needles, twigs, bark and moss. (0 to 2 inches thick)
Oa--0.5 to 1 inch; highly decomposed organic material. (0 to 2 inches thick)
E--1 to 4 inches; dark gray (10YR 4/1) ashy loamy sand, (volcanic ash), gray (7.5YR 5/1) dry; single grain; loose, nonsticky, nonplastic; few very fine and fine roots; NaF pH less than 9.2; very strongly acid (pH 5.0); abrupt smooth boundary. (1 to 4 inches thick)
Bhs1--4 to 7 inches; dark reddish brown (5YR 3/3) ashy sandy loam (volcanic ash), brown (7.5YR 4/4) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; 5 percent pebbles; many very fine, fine, medium and coarse roots; NaF pH 12.0; strongly acid (pH 5.2); abrupt smooth boundary. (2 to 6 inches thick)
Bhs2--7 to 11 inches; dark reddish brown (5YR 3/3) ashy sandy loam, (volcanic ash), yellowish brown (10YR 5/6) dry; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; few very fine and many fine and medium roots; NaF pH 12.0; moderately acid (pH 5.6); clear irregular boundary. (5 to 9 inches thick)
2Bs--11 to 22 inches; brown (7.5YR 4/4) very gravelly loam, yellowish brown (10YR 5/6) dry; moderate medium subangular blocky structure; soft, very friable, slightly sticky, slightly plastic, weakly smeary; many fine medium and coarse roots; 30 percent hard angular pebbles, 10 percent cobbles; NaF pH 11.5; moderately acid (pH 5.8); clear smooth boundary. (0 to 15 inches thick)
2BC--22 to 37 inches; dark yellowish brown (10YR 4/4) extremely gravelly sandy loam, very pale brown (10YR 7/4) dry; weak fine subangular blocky structure; very soft, very friable, slightly sticky, slightly plastic, moderately smeary; few very fine and fine roots; few very fine and common fine interstitial pores; 55 percent angular hard pebbles, 10 percent cobbles; NaF pH 11.5; moderately acid (pH 5.8); clear smooth boundary. (10 to 20 inches thick)
2C--37 to 61 inches; yellowish brown (10YR 5/4) very gravelly loam, very pale brown (10YR 7/4) dry; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic, moderately smeary; common fine continuous tubular pores; 10 percent hard angular cobbles, 40 percent hard angular pebbles, 5 percent stones; NaF pH 11.5; moderately acid (pH 5.8); clear smooth boundary.
TYPE LOCATION: Snoqualmie Pass Area, Pierce County, Washington; 1,400 feet west and 1,250 feet south of the northeast corner of sec. 20, T. 20 N., R. 8 E.
RANGE IN CHARACTERISTICS: Rock fragments, including hard cinders in the control section, average from 35 to 70 percent by volume. They are mostly angular but some are rounded. The mean annual soil temperature is 42 to 46 degrees F. The upper 7 to 14 inches of the solum has an estimated moist bulk density of 0.65 to 1.00 g/cc, volcanic glass content of 30 to 60 percent, acid oxalate extractable aluminum plus one-half the iron of more than 2.0 percent and 15 bar water retention of 5 to 12 percent on air dried samples.
The E horizon has hue of 10YR or 7.5YR, value of 4 to 7 moist and 5 to 8 dry, and chroma of 0 through 2 moist or dry. There is tonguing of this horizon into the Bhs horizon in some pedons. Rock fragments range from 0 to 25 percent. Reaction is very strongly acid or strongly acid.
The Bhs horizon is 7 to 12 inches thick and has hue of 5YR or 7.5YR, value of 3 to 5 moist, 4 to 6 dry, and chroma of 3 through 6 moist or dry. It is single grain or has weak subangular blocky structure. It is ashy loamy sand or ashy sandy loam. It is very strongly acid to moderately acid.
The 2Bs and 2BCs horizons have hue of 5YR through 10YR, value of 3 or 4 moist, and chroma of 3 through 6 moist. Texture is very gravelly loam, extremely gravelly sandy loam, very gravelly sandy loam or extremely gravelly loam. They are strongly acid to slightly acid.
The 2C horizon has hue of 10YR or 2.5Y, value of 6 through 8 dry and 3 through 5 moist, and chroma of 3 through 6 moist or dry. It is very gravelly sandy loam, very gravelly loam,, or extremely gravelly loam. It averages 30 to 50 percent pebbles and 10 to 20 percent cobbles. The coarse fragments are generally colluvial in the upper portion of this horizon and residual from bedrock in the lower portion. Reaction is strongly acid to slightly acid.
COMPETING SERIES: These are the Conto, Nimue and Springsteen series. Conto soils form in volcanic ash over glacial till. Conto soils have an ashy sandy loam or ashy silt loam mantle. Nimue soils are similar and need more review for separation; they have a mean annual soil temperature of 39 to 42 degrees F. Springsteen series are moderately deep to bedrock.
GEOGRAPHIC SETTING: Playco soils are on mountain slopes at elevations of 2,500 to 3,600 feet, the lower limit of the elevation range being on northerly and easterly exposures. Slopes range from 5 to 90 percent. The slopes are dissected in some areas. Playco soils formed in volcanic ash and pumice mixed with colluvium from extrusive igneous rocks. The climate is maritime influenced with cold, wet winters, and cool, moist summers. The mean January temperature is about 27 degrees F, the mean July temperature is about 60 degrees F, and mean annual air temperature is about 42 degrees F. Average annual precipitation is 75 to 90 inches, with a considerable portion of this being in the form of snow. The growing season (28 degrees F) is 110 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cattcreek, Cotteral, Foss, Haywire, Nagrom, Pitcher, and Spukwush soils, and the competing Nimue soils. Cattcreek soils are cindery over medial-skeletal. Cotteral soils are cindery over medial. Foss soils are medial over loamy-skeletal. Haywire and Nagrom soils have a lithic contact at 20 to 40 inches. Pitcher soils are frigid. Spukwush soils are ashy over loamy.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability, slow to medium runoff.
USE AND VEGETATION: Used for timber production, watershed, and wildlife habitat. Vegetation is western hemlock, Douglas-fir, noble fir, and Pacific silver fir, with an understory of Pacific yew, Oregon-grape, salal, huckleberry, western swordfern, devils club, trillium, montia, and mosses.
DISTRIBUTION AND EXTENT: Western slopes of the Cascade Mountains in west central Washington. Series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Snoqualmie Pass Area; Pierce County, Washington, 1979.
REMARKS: Partial laboratory data is available--NSSL #797460-62. Diagnostic horizons and features recognized in this pedon are an albic horizon from 1 to 4 inches and a spodic horizon 4 to 22.