LOCATION MULTORPOR OREstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Typic Udorthents
TYPICAL PEDON: Multorpor very stony coarse sand, forested. (Colors are for moist soil unless otherwise noted.)
0--1/2 inch to 0; loose litter of needles, twigs, cones, leaves, etc.
A--0 to 1 inch; very dark gray (10YR 3/1) extremely stony coarse sand, gray (10YR 5/1) dry; few light gray (10YR 7/1) sand particles; single grained; loose; common fine, medium and large roots; many fine and very fine irregular pores; 60 percent gravel, cobbles and stones; strongly acid (pH 5.3); abrupt wavy boundary. (1/2 to 2 inches thick)
AC--1 to 10 inches; dark grayish brown (10YR 4/2) extremely stony coarse sand, gray (10YR 6/1) dry; variegated with very dark grayish brown (10YR 3/2), light gray (10YR 7/1), and dark gray (10YR 3/1); single grained; loose; many fine, medium, and large roots; many fine and very fine irregular pores; 60 percent gravel, cobbles and stones; strongly acid (pH 5.5); gradual wavy boundary. (0 to 12 inches thick)
C--10 to 60 inches; very dark gray (10YR 3/1) and very dark grayish brown (10YR 3/2) extremely stony coarse sand, gray (10YR 6/1) and few very dark gray (10YR 3/1) and light gray (10YR 7/1) colored sand grains dry; single grained; loose; few roots; many fine and very fine irregular pores; 60 percent gravel, cobbles, and stones; medium acid (pH 5.9).
TYPE LOCATION: Clackamas County, Oregon; along the Lost Creek sale road; unsurveyed section 20, T. 2 S., R. 8 E., W. M.
RANGE IN CHARACTERISTICS: The soils are usually moist and are dry between depths of 12 and 35 inches for less than 45 consecutive days following the summer solstice. The mean annual soil temperature ranges from 47 to 50 degrees F. Depth to bedrock is greater than 60 inches. The particle-size control section is very cobbly coarse sand or extremely stony coarse sand with 45 to 80 percent rock fragments. Stones or cobbles are dominant sizes of rock fragments.
The A horizon has value of 3 or 4 and chroma of 1 or 0. It is extremely stony coarse sand or very cobbly loamy sand. It is very strongly acid or strongly acid.
The AC horizon has value of 3 through 5 moist and chroma of 1 or 2. Few fine variegations of dark yellowish brown and brown are in the upper few inches of the profile in some pedons.
The C horizon is similar to the AC horizon in color except that the dominant chroma is 1 moist and dry.
It is strongly acid or medium acid.
COMPETING SERIES: These are the Bonaparte, Hinckley, Manchester, Otisville, Quonset, and Speelyai series. Bonaparte, Hinckley and Otisville soils have Bw horizons with chroma of 3 or more. Manchester soils have hue of 5YR or redder in the Bw and C horizons. Quonset soils receive 40 to 50 inches of precipitation and have sola 15 to 50 inches thick. Speelyai soils are 9 to 20 inches deep to cemented horizons.
GEOGRAPHIC SETTING: The Multorpor soils are along high gradient streams and have slopes of 0 to 10 percent. Elevations are 500 to 2000 feet. The soils formed in stony, coarse-textured alluvium less than 1,000 years old and weathered from intermediate and basic igneous rocks. The climate is humid. Mean annual precipitation ranges from 8 to 120 inches, falling as rain in the autumn and spring, and snow or rain in the winter. Rainfall amounts are relatively low in the summer. The mean January temperature is 33 degrees F. The mean July temperature
is 63 degrees F. The mean annual temperature is 45 to 48 degrees F. The frost-free period is 80 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the
Crutch soil Crutch soils have a spodic horizon and a strongly
consolidated C horizon at 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Excessively well drained; slow runoff; rapid permeability; some areas are subject to occasional flooding for brief periods.
USE AND VEGETATION: Multorpor soils are used for recreation and wildlife. The overstory vegetation is scattered lodgepole pine with widely spaced stunted Douglas-fir, western hemlock, western redcedar and red alder. The understory vegetation is dominated by manzanita and lichens or moss.
DISTRIBUTION AND EXTENT: The Cascade Mountains of northwest Oregon. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Clackamas County, Oregon (Bull Run - Sandy Area), 1976.