LOCATION MUKILTEO WAEstablished Series
TAXONOMIC CLASS: Dysic, mesic Typic Haplohemists
TYPICAL PEDON: Mukilteo muck - pasture. (Colors are for moist soil unless otherwise noted.)
Oa1--0 to 2 inches; dark yellowish brown (10YR 4/4) sapric material; about 20 percent fibers, 10 percent rubbed; about 70 percent live fine fibrous roots; very strongly acid (pH 4.5); abrupt smooth boundary. (0 to 2 inches thick)
Oa2--2 to 6 inches; dark reddish brown (5YR 2/2) sapric material; about 50 percent fibers, 6 percent rubbed; moderate fine angular blocky structure; friable; many fine roots; very strongly acid (pH 4.5); abrupt smooth boundary. (2 to 14 inches thick)
Oe1--6 to 11 inches; dark reddish brown (5YR 3/2) hemic material; about 80 percent fibers, 20 percent rubbed; weak fine subangular blocky structure; friable; common fine roots; very strongly acid (pH 4.6); clear smooth boundary. (2 to 8 inches thick)
Oe2--11 to 42 inches; dark reddish brown (5YR 3/2) hemic material; about 65 percent fibers, 20 percent rubbed; massive; friable; few fine roots to 24 inches; very strongly acid (pH 4.6); clear smooth boundary. (28 to 40 inches thick)
Oe3--42 to 72 inches; dark reddish brown (5YR 3/2) hemic material; about 60 percent fibers, 24 percent rubbed; massive; friable; very strongly acid (pH 4.8)
TYPE LOCATION: Thurston County, Washington; 3 miles northeast of Olympia, about 600 feet north and 500 feet west of the southwest corner of sec. 12, T. 18 N., R. 2 W.
RANGE IN CHARACTERISTICS: The organic material in which this soil formed ranges in thickness from 52 inches to more than 10 feet. Mean January soil temperature is 32 degrees F., mean July temperature is 59 degrees F., and mean annual soil temperature at a depth of 20 inches ranges from 47 to 52 degrees F. These soils are usually saturated with water. They are strongly acid or very strongly acid. Fibers are mostly sedge and moss.
The surface tier has hue of 5YR or 7.5YR, value of 2 or 3, and chroma of 1 or 2. It commonly has one or more layers of sapric material but ranges from sapric to fibric material. It has weak to moderate blocky structure.
The subsurface tiers are hemic materials, have 5YR to 10YR hue, value and chroma ranging from 2 through 4. The rubbed fiber content averages from 16 to 60 percent.
The bottom tier is similar in color and fiber content to the subsurface tier, but is generally higher in fiber content.
COMPETING SERIES: These are the Napoleon series in the same family and the Dupont, McMurray, Orcas, Semiahmoo, and Seattle series in other families. Napoleon soils have a mean January temperature of about 26 degrees F and a mean July temperature of about 71 degrees F. Dupont soils have a limnic layer more than 2 inches thick in the control section. McMurray and Seattle soils are euic. In addition, McMurray soils have coarse wood fragments in the control section. Orcas soils have a fibric control section. Semiahmoo soils have a sapric control section and are euic.
GEOGRAPHIC SETTING: The Mukilteo soils are mostly in depressional areas of glacial uplands and some are in river valleys. Elevations range from sea level to 1,000 feet. Mukilteo soils formed in organic materials derived mostly from sedge, sphaguum and moss. These soils are in a mild humic climate having cool dry summers and mild wet winters. Average annual precipitation is 40 to 70 inches. The mean January temperature is about 36 degrees F. The mean July temperature is about 64 degrees F. The mean annual temperature is about 50 degrees F. The frost-free (32 degrees F.) season is 150 to more than 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Edmonds, McKenna, and Norma soils and the competing Dupont, Seattle, and Semiahmoo soils. Edmonds, McKenna, and Norma soils are mineral soils.
DRAINAGE AND PERMEABILITY: Very poorly drained; ponded; moderate permeability.
USE AND VEGETATION: Some areas have been cleared and drained and are used for hay, pasture, and blueberries. Native vegetation is red alder, western redcedar and western hemlock, with an understory of willow, Douglas spirea, cattail, sedges, rushes, trailing blackberry, red elderberry and devilsclub. Some ponded areas are not wooded and grow willow, cattail, rush, sedge, and Douglas spirea.
DISTRIBUTION AND EXTENT: This series is of moderate extent in the Puget Sound Basin of western Washington.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Snohomish County, Washington, 1938.