LOCATION HUMPTULIPS WAEstablished Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, isotic over mixed, nonacid, mesic Typic Udifluvents
TYPICAL PEDON: Humptulips silt loam, pasture. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 8 inches; dark grayish brown (10YR 4/2) silt loam, light yellowish brown (10YR 6/4) dry; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common medium and fine roots; many fine interstitial pores; neutral (pH 6.6); abrupt smooth boundary. (6 to 8 inches thick)
C1--8 to 12 inches; dark brown (10YR 4/3) silt loam, pale brown (10YR 6/3) dry; weak fine subangular blocky structure; hard, firm, slightly sticky and nonplastic; many fine and medium roots; few fine interstitial and tubular pores; thin strata of loose sand and loamy sand; neutral (pH 6.8); clear smooth boundary. (3 to 6 inches thick)
C2--12 to 26 inches; dark yellowish brown (10YR 4/4) silt loam, plae brown (10YR 6/3) dry; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; few fine roots; few fine interstitial and tubular pores; thin strata of loose sand; and loamy sand; neutral (pH 6.8); clear smooth boundary. (8 to 24 inches thick)
IIC3--26 to 48 inches; dark yellowish brown (10YR 4/4) very gravelly sand, light brownish gray (2.5Y 5/2) dry; single grained; loose; few fine roots; 75 percent hard waterworn pebbles consisting of graywacke and basalt; neutral (pH 7.0).
TYPE LOCATION: Grays Harbor County, Washington; 4 miles northwest of Montesano on Wynoochee Valley Road and across Black River bridge; northwest corner sec. 35, T.18N., R.8W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 47 degrees to 51 degrees F. Moist and dry hue is 10YR or 2.5Y. The upper part of the control section is silt loam and contains less than 18 percent clay and between 15 and 40 percent fine and coarse sand, and less than 5 percent rock. The C horizon is silt loam stratified with fine sandy loam to sand. The IIC horizon is very gravelly sand or very gravelly loamy sand. The Ap and C horizons have value of 4 through 6 dry, and chroma of 2 through 4 moist and 2 through 6 dry. The have mainly weak subangular blocky structure or are massive, but the IIC horizon is single grained.
COMPETING SERIES: These are the Grehalem, Hoh, and Huel soils in other families. All of these soils lack contrasting textures in the 10- to 40-inch control section.
GEOGRAPHIC SETTING: These soils are on nearly level flood plains at elevations of 10 to 50 feet, and are subject to periodic stream overflow. They formed in mixed medium textured alluvium. Humptulips soils occur in a humid climate with relatively cool summers and mild wet winters. Annual precipitation is 60 to 120 inches, average January temperature is 39 degrees F., average July temperature is 60 degrees F., mean annual temperature is 49 degrees F., and the growing season (28 degrees F.) is 180 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Grehalem soils.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow runoff; moderate permeability.
USE AND VEGETATION: Used mostly for sprinkler irrigated forage crops.
DISTRIBUTION AND EXTENT: Western Washington; series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Grays Harbor County, Washington, 1970.