LOCATION NAGROM WAEstablished Series
TAXONOMIC CLASS: Ashy over loamy-skeletal, amorphic over isotic Andic Haplocryods
TYPICAL PEDON: Nagrom sandy loam - in a regenerated clear cut area on a 20 percent northwest-facing convex slope at an elevation of 3,320 feet. The soil was moist when described. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures)
Oi--1 1/2 to 1/2 inch; leaves, needles, twigs, and moss; abrupt smooth boundary. (1/2 to 3 inches thick)
Oa--1/2 inch to 0; decomposed organic litter, abrupt smooth boundary. (1/2 to 2 inches thick)
E--0 to 2 inch; dark grayish brown (10YR 4/2) loamy sand (volcanic ash and pumice), light brownish gray (10YR 6/2) dry; single grain; loose, weakly smeary; many very fine, fine, and common medium roots; strongly acid (pH 5.4); abrupt wavy boundary. (0 to 6 inches thick)
Bhs--2 to 4 inches; dark reddish brown (5YR 3/2) loam (volcanic ash and pumice), dark reddish brown (5YR 3/3) dry; moderate fine subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic, moderately smeary; common very fine, fine, medium, and coarse roots; 5 percent pebbles; very strongly acid (pH 4.9); clear irregular boundary. (1 to 5 inches thick)
Bs--4 to 7 inches; dark reddish brown (5YR 3/4) loam, strong brown (7.5YR 5/6) dry; moderate fine subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic, moderately smeary; common very fine, fine, medium, and coarse roots; 10 percent pebbles; strongly acid (pH 5.4); clear irregular boundary. (3 to 10 inches thick)
BCs--7 to 23 inches; dark yellowish brown (10YR 4/4) gravelly loam, light yellowish brown (10YR 6/4) dry; moderate coarse subangular blocky structure; soft, friable, slightly sticky and slightly plastic, weakly smeary; few very fine and fine roots; 25 percent pebbles and 5 percent cobbles; moderately acid (pH 5.8); clear smooth boundary. (6 to 16 inches thick)
2C--23 to 38 inches; yellowish brown (10YR 5/4) very gravelly loam, very pale brown (10YR 7/4) dry; weak medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic, weakly smeary; 40 percent pebbles and 10 percent cobbles; moderately acid (pH 5.8); abrupt smooth boundary. (8 to 16 inches thick)
2R--38 inches; fractured andesite.
TYPE LOCATION: Snoqualmie Pass Area, King County, Washington; on a spur ridge off Grass Mountain; 1,300 feet west and 400 feet south of the northeast corner sec. 20, T. 20 N., R. 8 E.
RANGE IN CHARACTERISTICS: Depth to a lithic contact ranges from 20 to 40 inches. The control section averages from 35 to 60 percent rock fragments, which include hard cinders. Mean annual soil temperature ranges from 41 to 45 degrees F and mean summer soil temperature is less than 47 degrees F. Pedons range from weakly smeary to moderately smeary throughout.
The E horizon is weakly expressed or lacking in some pedons. It has hue of 10YR or 7.5YR, value of 4 through 6 moist, 6 or 7 dry, and chroma of 1 or 2 moist or dry. It contains 0 to 15 percent hard cinders and pebbles. There is tonguing of the E horizon into the B horizon in some pedons.
The Bhs horizon has hue of 5YR or 7.5YR, value of 3 or 4 moist and 3 through 5 dry, and chroma of 2 through 4 moist or dry. It is sandy loam, loam, gravelly sandy loam,or gravelly loam (volcanic ash and pumice) and contains 0 to 30 percent pebbles and hard cinders. Reaction is very strongly acid or strongly acid.
The Bs horizon has hue of 5YR or 7.5YR, value of 3 or 4 moist, and chroma of 4 through 6 moist. Texture is sandy loam, loam, or gravelly loam with 10 to 35 percent pebbles and hard cinders. It is very strongly acid, strongly acid, or moderately acid.
The BC horizon is gravelly loam, gravelly sandy loam, or very gravelly loam. It contains 25 to 50 percent pebbles and 5 to 10 percent cobbles.
The 2C horizon has hue of 2.5Y or 10YR, value of 4 or 5 moist, 6 through 8 dry, and chroma of 2 through 4 moist or dry. It is very gravelly loam or very gravelly silt loam with 40 to 50 percent pebbles and 5 to 10 percent cobbles.
COMPETING SERIES: These are the Nimue and Playco series. Nimue and Playco soils are more than 40 inches deep.
GEOGRAPHIC SETTING: Nagrom soils are on ridge crests and mountain slopes at elevations of 2,400 to 3,600 feet. They formed in residuum and colluvium from andesite, basalt and breccia with volcanic ash and pumice in the upper part. Mean January temperature is 27 degrees F, the mean July temperature is 60 degrees F, the mean annual temperature is 42 degrees F. Average annual precipitation is 75 to 100 inches, with the majority as snow in the winter months. The frost-free season is 110 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Foss, Haywire, Kindy, Littlejohn, Nimue, Pitcher, and Spukwush and the competing Playco soils. Foss soils are medial over loamy-skeletal. Haywire soils have more than 6 percent organic carbon throughout the upper 12 inches of the spodic horizon. Kindy soils have a paralithic contact with dense compact glacial till at 20 to 40 inches. Littlejohn and Pitcher soils are frigid. Spukwush soils are a shy over loamy. Nimue soils are deep.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff, moderate permeability.
USE AND VEGETATION: Used for timber production, wildlife habitat and watershed. Vegetation is western hemlock, noble fir, Douglas-fir, and Pacific silver fir, with an understory of huckleberry, common beargrass, Oregon-grape, salal, western swordfern, trillium, deer fern, and moss.
DISTRIBUTION AND EXTENT: Western slopes of the Central Cascade Mountains in Washington. Series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Snoqualmie Pass Area, King County, Washington, 1986.
REMARKS: Partial laboratory data are available on these soils. Laboratory numbers S79WA-033-008, 80T7408-7409. Diagnostic horizons and features recognized in this pedon are an albic horizon from the mineral surface to 2 inches, a spodic horizon from 2 to 23 inches, and a lithic contact at 38 inches. The upper part of the spodic horizon from 2 to 4 inches is 2.1 percent free iron and 10.4 percent organic carbon. The spodic horizon meets chemical criteria for a spodic horizon.