LOCATION HARTILL WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Andic Haploxerepts
TYPICAL PEDON: Hartill ashy silt loam - woodland. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inch; needles, leaves, and twigs; slightly acid (pH 6.5). (0 to 2 inches thick)
Oe--1 to 2 inches; partially decomposed needles, leaves, and twigs; slightly acid (pH 6.5); abrupt smooth boundary. (0 to 1 inch thick)
A--2 to 2.5 inches; light gray (10YR 7/1) ashy very fine sandy loam, dark gray (10YR 4/1) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine pores; neutral (pH 6.6); abrupt wavy boundary. (0 to 6 inch thick)
Bw1--2.5 to 9 inches; pale brown (10YR 6/3) ashy silt loam, dark brown (10YR 4/3) moist; weak fine and medium granular structure; soft, very friable, slightly sticky and nonplastic; weakly smeary; many fine and medium and few coarse roots; many fine and medium pores; 5 percent shale fragments; neutral (pH 6.6); clear wavy boundary. (4 to 8 inches thick)
Bw2--9 to 14 inches; pale brown (10YR 6/3) ashy silt loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; weakly smeary; many fine and medium and few coarse roots; many fine and medium pores; 15 percent shale fragments; slightly acid (pH 6.4); clear wavy boundary. (4 to 8 inches thick)
2Bw3--14 to 27 inches; very pale brown (10YR 7/4) shaly loam, yellowish brown (10YR 5/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium and few coarse roots; common fine and medium pores; 20 percent shale fragments and 10 percent flagstone; slightly acid (pH 6.4); clear wavy boundary. (10 to 15 inches thick)
2C--27 to 39 inches; pale yellow (2.5Y 7/4) very shaly loam, light olive brown (2.5Y 5/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; few fine and medium pores; 40 percent shale fragments and 10 percent flagstone; slightly acid (pH 6.4); clear wavy boundary. (10 to 15 inches thick)
2R--39 inches; fractured phyllite with fines in some voids.
TYPE LOCATION: Stevens County, Washington; 1,200 feet south and 1,800 feet west of the northeast corner of section 23, T. 30 N., R. 41 E., WM.
RANGE IN CHARACTERISTICS: Depth to a lithic contact is 20 to 40 inches. The mean annual soil temperature is 43 to 46 degrees F. The mantle of volcanic ash and loess is 7 to 14 inches thick and has an estimated moist bulk density of 0.65 to 0.85g/cc, volcanic glass content of 30 to 60 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 1.0 to 2.0 percent, and 15-bar water retention of 5 to 12 percent for air dried samples. The soil is usually moist in all horizons but is dry in all parts between depths of 4 and 12 inches for 45 to 60 consecutive days following the summer solstice. The particle-size control section is 35 to 50 percent rock fragments. The soil is neutral or slightly acid throughout.
The A horizon has hue of 10YR or 2.5YR, value of 5 through 7 dry, 3 through 5 moist, and chroma of 1 through 4. The A horizon in this pedon is Mt. St. Helens T or W ash, the Mt. St. Helens ash is absent in the A horizon is some pedons.
The Bw horizon has hue of 10YR or 7.5YR, value of 5 or 6 dry, 3 through 5 moist and chroma of 2 through 4 moist, 3 or 4 dry. It is ashy silt loam or ashy loam. It has 5 to 15 percent channers or shale fragments.
The 2Bw horizon has hue of 10YR or 2.5Y, value of 5 through 7 dry, 4 or 5 moist, and chroma of 3 o r 4 moist or dry. It is loam or sandy loam. Rock fragments range from 15 to 60 percent.
The 2C horizon has hue of 10YR or 2.5Y, value of 6 or 7 dry, 4 through 6 moist, and chroma of 3 or 4, dry or moist. It is loam or sandy loam modified by 25 to 50 percent shale fragments. Flagstones range from 5 to 25 percent.
COMPETING SERIES: These are the Belzar, Kloochman, McCree, Newbell, Newhorn, Ohscow, Oxerine, Redriver, Talls, Threemile, Wilma, and Wilmont series. Belzar soils are slightly alkaline or moderately alkaline in the 2C horizon. Kloochman and Oxerine soils are dry for 60 to 75 consecutive days. McCree, Newbell, Newhorn, Ohscow, Talls, Threemile, and Wilmont soils are more than 40 inches deep. Redriver soils are dry for 90 consecutive days. Wilma soils lack shaly rock fragments, are 35 to 60 percent angular granitic rock fragments in the particle-size control section, and are dry for 60 to 75 consecutive days.
GEOGRAPHIC SETTING: Hartill soils are on ridges, shoulders, and backslopes of mountains at elevations of 2,000 to 4,800 feet. Slopes are 0 to 65 percent. These soils formed in colluvium and residuum derived from shale, phyllite, graywacke, and quartzite with a mantle of volcanic ash. They are in a continental climate having warm, dry summers and cold, moist winters. Mean annual precipitation is 20 to 35 inches. Mean annual temperature is 42 to 45 degrees F, and average frost-free period is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aits, Elbowlake, Huckleberry, Nevine, and Raisio soils, and the competing Oxerine and Wilmont soils. Aits, Elbowlake, and Nevine soils are deeper than 60 inches to bedrock. In addition, Elbowlake and Nevine soils have a mantle of volcanic ash more than 14 inches thick. Huckleberry soils are cryic and medial over loamy-skeletal. Raisio soils have a mollic epipedon and are mesic.
DRAINAGE AND PERMEABILITY: Well drained; very slow to very rapid runoff; moderate permeability.
USE AND VEGETATION: Used for timber production, grazing, wildlife habitat, and watershed. Some small areas are cleared and used for pasture and hay or dryland crops. The natural vegetation is Douglas-fir, ponderosa pine, western larch, and grand fir, with an understory of common snowberry, willow, huckleberry, redstem ceanothus, pinegrass, creambush oceanspray, white spirea, pachystima, and rose.
DISTRIBUTION AND EXTENT: Northeastern Washington. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Stevens County, Washington, l978.
REMARKS: Diagnostic horizons and features recognized in this pedon area an ochric epipedon formed in Mt. St. Helens T or W ash from 2 to 2.5 inches. A cambic horizon formed in volcanic ash from 2.5 to 14 inches. Rock fragments in the 10 to 37 inches particle-size control section average 36 percent.