LOCATION LAKEFORK OR
Established Series
IRD. JLW/RJO/DAL/KMS
01/2019
LAKEFORK SERIES
Landscape--mountains
Landform--mountain slopes, moraines of glaciated mountain slopes
Slope--5 to 90 percent
Parent material--thick mantle of volcanic ash over till derived from mixed sources
Mean annual precipitation--about 1150 mm
Mean annual air temperature--about 5 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy-skeletal over loamy-skeletal, amorphic over isotic, frigid Typic Udivitrands
TYPICAL PEDON: Lakefork gravelly ashy silt loam in an area of woodland, on a 52-percent, east-facing slope at an elevation of 1707 m
Oi--0 to 8 cm; needles and twigs
A--8 to 23 cm; gravelly ashy silt loam, brown (10YR 4/3) dry, very dark grayish brown (10YR 3/2) moist; weak medium and fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine roots; few fine irregular pores; 30 percent gravel; slightly acid (pH 6.5); clear smooth boundary
AB--23 to 51 cm; very gravelly ashy silt loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4) moist; weak medium and fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few coarse and common medium, fine, and very fine roots; few fine tubular pores; 30 percent gravel and 10 percent cobbles; neutral (pH 7.0); clear smooth boundary
Bw--51 to 97 cm; extremely stony ashy silt loam, yellowish brown (10YR 5/6) dry, dark yellowish brown (10YR 3/4) moist; weak fine and very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine, fine, medium, and coarse roots; few fine irregular pores; 30 percent gravel, 30 percent cobbles, and 20 percent stones; slightly acid (pH 6.5); clear smooth boundary
2EBb--97 to 119 cm; extremely stony sandy loam, brownish yellow (10YR 6/6) dry, dark yellowish brown (10YR 3/6) moist; weak medium and fine subangular blocky structure; soft, friable, slightly sticky and nonplastic; few very fine, fine, medium, and coarse roots; few fine irregular and tubular pores; 35 percent gravel, 20 percent cobbles, and 25 percent stones; slightly acid (pH 6.5); gradual smooth boundary
2BCb--119 to 155 cm; extremely stony sandy loam, light yellowish brown (2.5Y 6/4) dry, olive brown (2.5Y 4/4) moist; weak medium and fine subangular blocky structure; soft, friable, slightly sticky and nonplastic; few very fine, fine, and medium roots; few fine irregular pores; 35 percent gravel, 20 percent cobbles, and 25 percent stones; slightly acid (pH 6.5)
TYPE LOCATION: Baker County, Oregon, about 810 m west and 520 m south of the northeast corner of section 30, T. 6 S., R. 46 E.; Cornucopia U.S. Geological Survey quadrangle; latitude 45.0174757, longitude -117.1343929, datum WGS 84 (coordinates and PLSS details estimated from a point on a hard copy map)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--about 4 to 7 degrees C
Mean summer soil temperature--about 9 to 12 degrees C
Mean winter soil temperature--about 0 to 3 degrees C
Soil moisture--dry 30 to 45 days in summer
Depth to unconsolidated till--35 to 90 cm from the mineral soil surface
Thickness of ash-influenced layers--35 to 90 cm
Estimated properties of layers influenced by volcanic ash
*Ammonium oxalate extractable Al + 1/2 Fe--1 to 3 percent
*0.02- to 2.0-mm fraction--40 to 60 percent
*Glass content in 0.02- to 2.0-mm fraction--60 to 90 percent
*1/3-bar bulk density--0.65 to 1.0 g/cm3
*Phosphate retention--40 to 90 percent
*15-bar water retention--5 to 12 percent (dried samples)
*8 x Si plus 2 x Fe--5 to 12 percent
Particle-size control section
*Ashy-skeletal upper part--35 to 90 cm thick; 5 to 8 percent clay; 45 to 80 percent rounded and subrounded rock fragments
*Loamy-skeletal lower part--13 to 65 cm thick; 7 to 16 percent clay; 60 to 80 percent rounded and subrounded rock fragments
A horizon
Moist color--10YR 3/2, 10YR 3/3, 10YR 3/4
Dry color--10YR 4/3, 10YR 5/3, 10YR 5/4
Fine-earth texture--ashy silt loam
Clay content--5 to 8 percent
Sand content--30 to 45 percent
Organic matter content--2 to 5 percent
Total rock fragment content--5 to 55 percent
Gravel content--5 to 35 percent
Cobble content--0 to 10 percent
Stone content--0 to 10 percent
Reaction--6.1 to 7.3
Thickness--3 to 25 cm
AB horizon
Thickness--0 to 30 cm
Bw horizon
Moist color--10YR 3/4, 10YR 4/3
Dry color--10YR 5/4, 10YR 5/6, 10YR 6/6
Fine-earth texture--ashy silt loam
Clay content--5 to 7 percent
Sand content--30 to 45 percent
Organic matter content--1 to 3 percent
Total rock fragment content--60 to 80 percent
Gravel content--15 to 30 percent
Cobble content--20 to 30 percent
Stone content--20 to 25 percent
Reaction--6.1 to 7.3
Thickness--13 to 55 cm
2EBb horizon
Moist color--10YR 3/6, 10YR 4/6, 10YR 5/4, 10YR 5/6, 2.5Y 4/4
Dry color--10YR 5/6, 10YR 6/4, 10YR 6/6, 2.5Y 5/4
Fine-earth texture--sandy loam, loam
Clay content--7 to 16 percent
Sand content--45 to 70 percent
Organic matter content--0.5 to 2.0 percent
Total rock fragment content--60 to 90 percent
Gravel content--20 to 50 percent
Cobble content--10 to 40 percent
Stone content--10 to 25 percent
Reaction--5.6 to 6.5
Thickness--22 to 55 cm
2BCb horizon
Moist color--10YR 4/6, 10YR 5/4, 2.5Y 4/4
Dry color--10YR 5/6, 10YR 6/6, 2.5Y 6/4
Fine-earth texture--sandy loam, loam
Clay content--8 to 20 percent
Sand content--50 to 70 percent
Organic matter content--0.5 to 1.5 percent
Total rock fragment content--60 to 90 percent
Gravel content--20 to 50 percent
Cobble content--15 to 25 percent
Stone content--10 to 25 percent
Reaction--5.6 to 6.5
Thickness--40 to 95 cm
COMPETING SERIES:
Ahrs--less than 60 percent glass
Harl--subangular rock fragments in particle-size control section; formed in volcanic ash over colluvium derived from basalt
GEOGRAPHIC SETTING:
Elevation--1225 to 1700 m
Climate--cold, wet winters; cool, moist summers
Mean annual precipitation--760 to 1300 mm
Mean annual air temperature--3 to 6 degrees C
Frost-free period--35 to 80 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Bigelk--on steeper, more south-facing slopes at lower elevations; mollic epipedon; 45 to 60 dry days
Bulgar--on gentler slopes and in more concave positions; less than 35 percent rock fragments in upper part of particle-size control section; rock fragments dominantly granite
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Saturation during normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high over moderately high
USE AND VEGETATION:
Use--timber production, watershed, wildlife habitat, livestock grazing, recreation
Native vegetation--grand fir, Douglas-fir, Engelmann spruce, ponderosa pine, western larch, lodgepole pine, subalpine fir, Douglas maple, big huckleberry, northern twinflower, heartleaf arnica, pathfinder, western meadow-rue, pinegrass, baldhip rose, darkwoods violet, sidebells wintergreen, starry false Solomon's seal, elk sedge, Columbia brome, sweetcicely, low Oregon grape, Ross' sedge, woodland strawberry, prince's pine
Plant association--dominantly ABGR/ACGL; may include ABGR/VAME, PICO(ABGR)/ALSI, ABGR/SPBE, or ABGR/CLUN
DISTRIBUTION AND EXTENT: Blue Mountains of northeastern Oregon; MLRA 10; small extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wallowa-Whitman National Forest, Oregon; 2018
REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Ochric epipedon
*Cambic horizon--zone from 23 to 97 cm
*Volcanic glass--zone from 8 to 97 cm
*Andic soil properties--zone from 8 to 97 cm
*Particle-size control section--zone from 8 to 108 cm
National Cooperative Soil Survey
U.S.A.