LOCATION PISGASHA                OR

Tentative Series
IRD. JRD/KMS/KLM
02/2025

PISGASHA SERIES

Landscape--mountains
Landform--mountain slopes
Slope--10 to 70 percent
Parent material--volcanic ash over colluvium
Mean annual precipitation--910 mm
Mean annual air temperature--3 degrees C
Depth class--very deep
Drainage class--moderately well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic

TAXONOMIC CLASS: Ashy, amorphic Alfic Vitricryands

TYPICAL PEDON: Pisgasha ashy loamy sand, supporting a lodgepole pine and subalpine fir plant community type, woodland; on a concave slope of 30 percent with a north aspect at about 1875 m elevation. (Colors are for air dry soil unless otherwise noted.)

Oi--0 to 1 centimeters; slightly decomposed needles and twigs

A--1 to 17 centimeters; brown (10YR 5/3) ashy loamy sand, dark yellowish brown (10YR 3/4) moist; weak subangular blocky structure parting to fine granular; loose, very friable, nonsticky and nonplastic; common fine roots; many fine irregular pores; 5 percent gravels; moderately acid (pH5.8); clear wavy boundary.

Bw1--17 to 38 centimeters; yellowish brown (10YR 5/4) ashy loamy sand, dark yellowish brown (10YR 3/4) moist; weak medium and coarse subangular blocky structure parting to fine granular; loose, very friable, nonsticky and nonplastic; few fine and common medium roots; many fine irregular pores; 5 percent gravels; moderately acid (pH 5.6); gradual smooth boundary.

Bw2--38 to 55 centimeters; brown (10YR 5/3) ashy loamy sand, dark yellowish brown (10YR 3/4) moist; weak medium and coarse subangular blocky structure parting to fine granular; loose, very friable, nonsticky and nonplastic; few fine and common medium roots; many fine irregular pores; 5 percent gravels; moderately acid (pH 6.0); gradual smooth boundary.

Bw3--55 to 116 centimeters; yellowish brown (10YR 5/4) ashy loamy sand, dark yellowish brown (10YR 3/4) moist; weak medium subangular blocky structure parting to fine granular; loose, very friable, nonsticky and nonplastic; few fine roots; many fine irregular pores; 10 percent gravels; moderately acid (pH 5.8); abrupt broken boundary.

C1--116 to 130 centimeters; pale yellow (2.5Y 7/4) ashy loamy sand, light yellowish brown (2.5Y 6/4) moist; massive parting to strong coarse subangular blocky structure, moderately hard, firm, nonsticky and nonplastic; no roots; common fine irregular pores; 10 percent medium, distinct, 10YR 5/8 (moist) iron-manganese masses; moderately acid (pH 5.8); clear wavy boundary.

C2--130 to 135 cm; very pale brown (10YR 8/3) ashy very fine sandy loam, very pale brown (10YR 7/3) moist; moderate thick platy; hard, firm, brittle, nonsticky and nonplastic; many fine and medium roots in a mat at top of horizon; moderately acid (pH 5.8); abrupt wavy boundary

2Ab--135 to 143 centimeters; dark brown (7.5YR 3/3) gravelly loam, very dark brown (7.5YR 2.5/3) moist; weak fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; very few very fine roots and very few coarse roots; few fine irregular pores; 20 percent gravel, 5 percent cobble; moderately acid (pH 6.0); abrupt wavy boundary.

2Btb--143 to 175 centimeters; dark yellowish brown (10YR 3/4) very cobbly clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; very few coarse roots; few fine irregular pores; many distinct, continuous clay films on ped faces and rock faces; 25 percent subangular gravels and 30 percent subangular cobbles; moderately acid (pH 5.6).

TYPE LOCATION: Wheeler County; about 2 km east of Mt Pisgah, Oregon in the Ochoco Mountains; about 5 km on the 2630 road from the 2630-450 junction; NE of SE of section 9, T. 13 S., R .21 E; latitude 44.4581170, longitude -120.2070420, WGS84 Datum (coordinates determined with a GPS)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--1 to 5 degrees C
Soil moisture--dry for less than 30 consecutive days during the four months following the summer solstice
Ochric epipedon
Depth to lithic contact--greater than 150 cm

Estimated properties of layers with andic soil properties
*Andic Soil Properties--upper boundary at mineral soil surface, 100 to 150 cm thick
*0.2 to 2.0 mm fraction--60 to 80 percent of fine earth
*P Retention--40 to 70 percent
*Acid oxalate Al + 1/2Fe--.4 to 2.0 percent
*Volcanic glass content in 0.2 to 2.0 mm fraction--30 to 50 percent
*Water content at 1500kPa (air dry)--10 to 12 percent

Particle Size Control Section (mineral soil surface to 100cm)
Upper part (ashy)--100 to 150 cm thick
*Clay content--5 to 18 percent
*Rock fragment content--0 to 15 percent

A horizon
*Hue--10YR moist or dry
*Value--4 or 5 dry, 2 or 3 moist
*Chroma--2 to 4 dry or moist
*Fine earth texture--loamy sand, sandy loam
*Clay content--5 to 18 percent
*Sand content--55 to 85 percent
*Organic matter content--1 to 4 percent
*Total rock fragments--0 to 15 percent
*Gravel content--0 to 15 percent
*Cobble content--0 to 10 percent
*Reaction--moderately acid
*Thickness--20 to 40 cm

Bw horizons
*Hue--10YR moist or dry
*Value--4 or 5 dry, 2 or 3 moist
*Chroma--2 to 4 dry or moist
*Fine earth texture--loamy sand, sandy loam
*Clay content--5 to 18 percent
*Sand content--55 to 85 percent
*Organic matter content--0.5 to 2 percent
*Total rock fragments--0 to 15 percent
*Gravel content--0 to 15 percent
*Cobble content--0 to 10 percent
*Reaction--moderately acid
*Thickness--30 to 60 cm

C horizons
*Hue-- 2.5Y, 7.5Y or 10YR moist or dry
*Value--6 to 8 dry, 4 to 6 moist
*Chroma--2 to 4 dry or moist
*Fine earth texture--coarse silt, very fine sandy loam, loamy sand
*Clay content--2 to 10 percent
*Sand content--Coarse silt textures have 5 to 15 percent sand; sandy loam and loamy sand textures have 65 to 85 percent sand
*Organic matter content--0.5 to 1 percent
*Total rock fragments--0 to 15 percent
*Gravel content--0 to 15 percent
*Cobble content--0 to 10 percent
*Reaction--moderately acid
*Thickness--15 to 30 cm

2Ab horizon
*Hue--7.5YR or 10YR moist or dry
*Value--3 or 4 dry 2 to 3 moist
*Chroma--3 or 4 dry, 2 to 4 moist
*Fine earth texture--sandy loam, loam
*Clay content--10 to 25 percent
*Sand content--40 to 70 percent
*Organic matter content--0.5 to 2 percent
*Total rock fragments--15 to 65 percent
*Gravel content--15 to 50 percent
*Cobble content--0 to 20 percent
*Stones or boulders--0 to 20 percent
*Reaction--moderately to slightly acid
*Thickness--10 to 20 cm

2Btb horizon
*Hue--10YR or 7.5YR
*Value--3 or 4 dry, 4 to 6 moist
*Chroma--3 or 4 dry or moist
*Fine earth texture--loam, clay loam, sandy clay loam
*Clay content-- 15 to 35 percent
*Sand content--30 to 65 percent
*Organic matter content--0.5 to 1 percent
*Total rock fragments--35 to 80 percent
*Gravel content--30 to 65 percent
*Cobble content--5 to 30 percent
*Stone or boulder content--0 to 20 percent
*Reaction--moderately to slightly acid

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:
Elevation--1650 to 2150 m
Aspect--typically north and east
Climate--cold, wet winters and cool, moist summers
Mean annual precipitation--760 to 1060 mm
Mean annual air temperature--2 to 6 degrees C
Frost-free period--10 to 45 days
Lithology--volcanic ash derived from Mt Mazama over residuum and colluvium derived from Columbia River Basalts

GEOGRAPHICALLY ASSOCIATED SOILS:
Pisgasprings--occur on mountain sideslopes and benches; 100 to 200 cm to lithic contact; 40 to 80 cm of volcanic ash over loamy colluvium
Wineburger--occur on benches and mountain side slopes; 100 to 150 cm to bedrock; xeric moisture regime

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage--moderately well drained
Saturation during normal years--episaturation occurring in April to July at 116 to 130 cm (C1 horizon)
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--High

USE AND VEGETATION:
Use--timber production, wildlife habitat, recreation
Potential native vegetation--Lodgepole pine, subalpine fir, grand fir, grouse huckleberry, elk sedge
Typical plant association--CAG111 Subalpine fir/Elk sedge; CES411 Subalpine fir/grouse huckleberry; Plant Associations of the Blue and Ochoco Mountains; USDA Forest Service

DISTRIBUTION AND EXTENT: Central Oregon, Ochoco Mountains (southwest Blue Mountains, MLRA 43C. The soil is of small extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES PROPOSED: Ochoco National Forest, Wheeler County, Oregon, 2015.

REMARKS:
Diagnostic horizons and features recognized in this pedon are
*Ochric epipedon
*Particle-size control section--the zone from 1 to 101 cm
*Andic soil properties--the zone from 1 to 135 cm
*Episaturation--116 to 130 cm
*Argillic horizon--143 to 175 cm (outside PSCS)

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National Cooperative Soil Survey
U.S.A.