LOCATION MODOCPOINT              OR

Tentative Series
Rev. KBC/BTH
11/2023

MODOCPOINT SERIES

Landscape--Intermontane basins
Landform--alluvial fans, stream terraces
Slope--0 to 5 percent
Parent material--alluvium derived from volcanic rock and volcanic ash
Mean annual precipitation--about 510 mm
Mean annual air temperature--about 6 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid
Soil moisture subclass--typic

TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Vitrandic Haploxerolls

TYPICAL PEDON: Modocpoint ashy coarse sandy loam on a cultivated alluvial fan with a slope of 2 percent and an elevation of 1272 m

A--0 to 15 cm; ashy coarse sandy loam, dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; moderate fine and medium granular structure; slightly hard, very friable, nonsticky and nonplastic; common very fine, fine, and medium roots throughout; common fine and medium dendritic tubular and coarse tubular pores; 12 percent mixed volcanic gravel; slightly acid (pH 6.5); gradual smooth boundary

AB--15 to 32 cm; gravelly ashy sandy loam, dark grayish brown (10YR 4/2) dry, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine and fine, and few medium roots throughout; common fine and medium dendritic tubular and coarse tubular pores; 25 percent mixed volcanic gravel; neutral (pH 6.6); gradual smooth boundary

Bw1--32 to 58 cm; gravelly ashy sandy loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4), moist; moderate medium subangular blocky structure; moderately hard, friable, nonsticky and nonplastic; common very fine and fine and few medium roots; common very fine and fine dendritic tubular pores; 20 percent dark yellowish brown (10YR 3/4), moist, clay bridges between sand grains; 15 percent fine and 15 percent medium mixed volcanic gravel; neutral (pH 7.0); gradual smooth boundary

Bw2--58 to 94 cm; very gravelly ashy sandy loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4), moist; moderate coarse subangular blocky structure; moderately hard, friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine dendritic tubular pores; 20 percent dark yellowish brown (10YR 3/4), moist, clay bridges between sand grains; 30 percent fine, 10 percent medium, and 5 percent coarse mixed volcanic gravel; neutral (pH 7.2); gradual smooth boundary

BC--94 to 150 cm; extremely gravelly ashy loamy sand, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4) moist; weak coarse subangular blocky structure; soft, friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine dendritic tubular pores; 35 percent fine, 20 percent medium, and 10 percent coarse mixed volcanic gravel, and 1 percent mixed volcanic cobbles; neutral (pH 7.2); gradual smooth boundary

C--150 to 205 cm; gravelly ashy loamy fine sand, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4) moist; massive structure; loose, friable, nonsticky and nonplastic; 2 percent dark yellowish brown (10YR 4/4), moist, iron-manganese masses with diffuse boundaries in matrix; 15 percent fine and 10 percent medium mixed volcanic gravel; neutral (pH 7.0)

TYPE LOCATION: Klamath County, Oregon; about 0.8 mile west of the junction of Highway 97 and Day School Road and 0.3 mile north of Day School Road; about 430 m north and 174 m east of the SW corner section 28, T. 35 S., R. 7 E.; Willamette Meridian; Agency Lake, Oregon USGS quadrangle; latitude 42.5045910 degrees north, longitude 121.8948940 degrees west, datum WGS 84 (coordinates derived from GPS unit).

RANGE IN CHARACTERISTICS:
*Average annual soil temperature--6 to 8 degrees C
*Soil moisture control section--20 to 80 cm; dry for 60 to 90 consecutive days within the four month period following the summer solstice; seasonally high water table (endosaturation) below the control section between March and June has an upper limit of 120 cm below the surface in normal years
*Mollic epipedon--18 to 49 cm thick
*Base saturation throughout the Mollic epipedon--75 to 100 percent by NH4OH
*Reaction--moderately acid to neutral

Estimated properties:
*Volcanic glass content--5 to 20 percent
*Acid oxalate Al+1/2Fe--0.2 to 0.4 percent
*Moist bulk density--1.0 to 1.2 g/cc
*15 bar water retention--10 to 15 percent on air dried samples

Particle-size control section:
*Clay content--5 to 17 percent
*Total rock fragment content--35 to 75 percent

A horizon(s)
*Value--4 or 5 dry, 2 or 3 moist
*Chroma--2 or 3 dry or moist
*Clay content--5 to 15 percent
*Gravel content--0 to 14 percent
*Paragravel content--0 to 5 percent
*Total rock and pararock fragment content--0 to 14 percent
*Thickness--10 to 49 cm

AB horizon(s) (where present)
*Value--4 or 5 dry, 2 or 3 moist
*Chroma--2 or 3 dry or moist
*Fine-earth texture--ashy loamy sand, ashy sandy loam, ashy loam
*Clay content--5 to 15 percent
*Gravel content--10 to 30 percent
*Paragravel content--0 to 5 percent
*Total rock and pararock fragment content--10 to 30 percent
*Thickness--0 to 20 cm

Bw horizon(s)
*Value--4 to 6 dry, 3 or 4 moist
*Chroma--2 to 4 dry or moist
*Fine-earth texture--ashy loamy sand, ashy coarse sandy loam, ashy sandy loam, ashy loam
*Clay content--5 to 17 percent
*Gravel content--10 to 55 percent
*Cobble content--0 to 5 percent
*Paragravel content--0 to 5 percent
*Total rock and pararock fragment content--10 to 55 percent
*Thickness--40 to 100 cm

BC horizon (where present)
*Value--4 to 6 dry, 3 or 4 moist
*Chroma--2 to 4 dry or moist
*Fine-earth texture--ashy loamy sand, ashy loamy fine sand, ashy coarse sandy loam, ashy sandy loam
*Clay content--5 to 13 percent
*Gravel content--25 to 75 percent
*Cobble content--0 to 5 percent
*Paragravel content--0 to 5 percent
*Total rock and pararock fragment content--25 to 75 percent
*Thickness--0 to 55 cm

C horizon
*Value--4 to 6 dry, 3 or 4 moist
*Chroma--2 to 4 dry or moist
*Fine-earth texture--ashy loamy sand, ashy loamy fine sand, ashy coarse sandy loam, ashy sandy loam
*Clay content--5 to 13 percent
*Gravel content--20 to 70 percent
*Cobble content--0 to 5 percent
*Paragravel content--0 to 5 percent
*Total rock and pararock fragment content--20 to 75 percent

COMPETING SERIES:
Bearspring--parent material is granitic; 90 to 120 frost-free days
Bigelk--lithologic discontinuity; soil moisture control section is dry for 45 to 60 days
Cassal--deep to densic contact; moderately well drained
Cherrycreek--deep to bedrock; thickness of the mollic epipedon is greater than 50 cm
Deck--moderately deep to lithic contact
Eastpine--moderately deep to bedrock
Egyptcreek--moderately deep to bedrock
Fredonyer--moderately deep to bedrock
Golfer--moderately deep to paralithic contact
Grubcreek--moderately deep to bedrock
Kettlecreek--deep to bedrock; lithologic discontinuity
Longs--deep to bedrock; thickness of the mollic epipedon is greater than 50 cm
McCrosket--deep to bedrock
Midpeak--moderately deep to bedrock; lithologic discontinuity
Mineral--moderately deep to bedrock
Peahke--moderately deep to bedrock
Piersonte--parent material is shale or schist; upper part of the Bw horizons has 18 to 30 percent clay and 50 to 70 percent shale fragments; lower part of the Bw horizons has 50 to 80% shale fragments
Porch--moderately deep to bedrock
Scoap--thickness of the mollic epipedon is at least 50 cm; 90 to 120 frost-free days
Shalrock--moderately deep to bedrock; lithologic discontinuity
Shilling--18 to 27 percent clay in the particle-size control section
Umatilla--25 to 35 percent clay in the particle-size control section; lithologic discontinuity
Webbgulch--moderately deep to bedrock
Yellcreek--influence of ash only in the upper part; lithologic discontinuity; thickness of the mollic epipedon is at least 50 cm

GEOGRAPHIC SETTING:
Elevation--1260 to 1300 m
Climate--cold, wet winters and warm, dry summers
Mean annual precipitation--455 to 560 mm
Mean annual air temperature--4.5 to 6.9 degrees C
Frost-free period--40 to 70 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Bly--100 to 200 cm to a duripan (deep or very deep); argillic horizon; alluvial fans and terraces
Chiloquin--90 to 110 cm to apparent high water table (moderately well drained); flood plains and terraces
Dragonfly--50 to 100 cm to apparent high water table (somewhat poorly drained); particle-size control section is ashy and non-skeletal; floodplains
Henley--50 to 100 cm to duripan (moderately deep); 50 to 110 frost-free days; stream terraces
Lobert--particle-size control section averages less than 15 percent coarse fragments; stream terraces
Ontko--saturated for 30 to 60 days in the spring; 10 to 50 cm to layers meeting aquandic subgroup criteria (very poorly or poorly drained); flood plains

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity--moderately high to very high

USE AND VEGETATION:
Use--timber production, livestock grazing, irrigated and dryland small grains, hay, pasture, homesites
Vegetation--ponderosa pine, big sagebrush, antelope bitterbrush, Ross's sedge, Idaho fescue,

DISTRIBUTION AND EXTENT: Klamath and Shasta Valleys and Basins, Oregon; MLRA 21; small extent

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES PROPOSED: Klamath County, Oregon, 2019
Origin of the name--Modoc Point is a named geographic feature (high point on a nearby scarp, and a landform feature that juts out into Upper Klamath Lake), a USGS quadrangle map name, and the name of a road near the type location of this soil series.

REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Mollic epipedon--A, AB horizons
*Cambic horizon--Bw1, Bw2 horizons
*Volcanic glass--all horizons
*Vitrandic subgroup criteria--all horizons
*Redoximorphic concentrations--C horizon
*Particle-size control section--the zone from 25 to 100 cm

ADDITIONAL DATA:
*NASIS Site ID: 2019OR035054
*NASIS Pedon ID: 2019OR035054

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National Cooperative Soil Survey
U.S.A.