LOCATION OATMAN OR

Established Series
Rev. RHB/AON/TDT
02/2025

OATMAN SERIES

Landscape--Cascade Mountains
Landform--volcanic cones, ground moraines, glaciated hillslopes, mountain slopes, cirque headwalls
Slope--0 to 90
Parent material--colluvium, till and residuum derived from basalt and andesite mixed with volcanic ash throughout Mean annual precipitation--about 1020 mm
Mean annual air temperature--about 5.5 degrees C
Depth class--deep to a duripan; or very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic

TAXONOMIC CLASS: Medial-skeletal, amorphic Typic Haplocryands

TYPICAL PEDON: Oatman cobbly medial loam, in coniferous forest, with a slope of 9 percent, at an elevation of 1750 m.

Oi--0 to 8 cm; slightly decomposed needles and twigs

A--8 to 13 cm; cobbly medial loam, dark brown (7.5YR 3/4) dry, dark brown (7.5YR 3/2) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine irregular pores; 14 percent gravel and 11 percent cobbles; slightly acid (pH 6.5); abrupt smooth boundary

AB--13 to 48 cm; cobbly medial loam, brown (7.5YR 4/4) dry, dark brown (7.5YR 3/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine irregular pores; 10 percent gravel and 15 percent cobbles; slightly acid (pH 6.5); clear smooth boundary

Bw1--48 to 84 cm; very cobbly medial sandy loam, brown (7.5YR 4/4) dry, dark brown (7.5YR 3/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common medium and coarse and many very fine and fine roots; many very fine irregular pores; 10 percent gravel and 30 percent cobbles; slightly acid (pH 6.3); gradual wavy boundary

Bw2--84 to 114 cm; very cobbly medial sandy loam, strong brown (7.5YR 4/6) dry, dark brown (7.5YR 3/4) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; common medium and coarse and many very fine and fine roots; many very fine irregular pores; 10 percent gravel and 35 percent cobbles; slightly acid (pH 6.2); gradual wavy boundary

BC--114 to 208 cm; very cobbly medial sandy loam, brown (7.5YR 5/4) dry, brown (7.5YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; few fine and medium roots; many very fine irregular pores; 15 percent gravel and 25 percent cobbles; moderately acid (pH 6.0)

TYPE LOCATION: Jackson County, Oregon; about 8 miles northeast of Hyatt Reservoir; about 91 m south and 100 m west of the northeast corner of sec. 26, T. 38 S., R. 4 E., Willamette Meridian; Little Chinquapin Mountain, Oregon, U.S. Geological Survey quadrangle; latitude 42.2427710 degrees, longitude -122.3083370 degrees, datum WGS 84 (coordinates estimated from PLSS details)

RANGE IN CHARACTERISTICS:

Mean annual soil temperature--5 to 7.8 degrees C
Mean summer soil temperature with an O horizon--6.7 to 8.3 degrees C
Mean summer soil temperature without an O horizon--10 to 14.4 degrees C
Moisture control section--dry for 30 to 45 consecutive days
Rock fragments--subrounded
Depth to restriction--100 to over 200 cm to an indurated duripan
*Base saturation--35 to 60 percent in mineral horizons (8 to 208 cm)
*Thickness of volcanic ash influenced layers--100 to over 200 cm (all horizons)

Estimated properties of layers influenced by volcanic ash
*1/3-bar bulk density--0.85 to 1.0 g/cm3 in A horizons; 1.1 to 1.4 g/cm3 in B and BC horizons
*Volcanic glass in 0.02 to 2.0 mm fraction--15 to 30 percent
*0.02 to 2.0 mm fraction--greater than 30 percent
*Ammonium oxalate extractable Al + 1/2Fe--3 to 5 percent
*Phosphate retention--75 to 100 percent
*15-bar water dry--15 to 30 percent (dried samples), 30 to 100 percent (undried samples)
*Acid oxalate extractable silica--2 to 3 percent

Surface Rock Fragments
*Stones--0 to 10 percent surface cover
*Boulders--0 to 5 percent surface cover

Particle-size control section
*Clay--4 to 20 percent clay
*Sand--40 to 75 percent sand; less than 50 percent of the 0.02 to 0.20 mm fraction is medium to very coarse sand
*Total fragments --35 to 65 percent

A and AB horizons
*Hue--10YR, 7.5YR, or 5YR
*Value--3 or 4 moist, 3 to 5 dry
*Chroma--2 to 4 moist, 3 or 4 dry
*Clay--7 to 20 percent
*Sand--30 to 50 percent
*Organic matter--0.5 to 10.0 percent
*Total fragments content--20 to 75 percent
*Gravel--10 to 50 percent
*Cobbles--0 to 50 percent
*Stones--0 to 40 percent
*1/3 bar Bulk Density--0.60 to 1.00 g/cc
*Reaction--5.6 to 6.5
*Thickness--A horizon, 5 to 10 cm; AB horizon, 12 to 38 cm

Bw horizons
*Hue--10YR, 7.5YR, or 5YR
*Value--3 or 4 moist, 4 to 6 dry
*Chroma--3 or 4 moist, 3 to 6 dry
*Fine-earth texture--medial sandy loam or medial loam
*Clay--4 to 20 percent
*Sand--30 to 75 percent
*Organic matter--0.1 to 2.0 percent
*Total fragments--35 to 75 percent
*Gravel--10 to 50 percent
*Cobbles--10 to 35 percent
*Stones--0 to 10 percent
*Reaction--5.6 to 6.5*Thickness--23 to 84 cm

BC horizons
*Hue--10YR, 7.5YR, or 5YR
*Value--3 or 4 moist, 4 to 6 dry
*Chroma--3 or 4 moist, 3 to 6 dry
*Fine-earth texture--medial sandy loam or medial loam
*Clay--2 to 15 percent
*Sand--40 to 75 percent
*Organic matter--0.1 to 1.0 percent
*Total fragments--35 to 75 percent
*Gravel--15 to 55 percent
*Cobbles--10 to 25 percent
*Stones--0 to 10 percent
*Reaction--5.6 to 7.3

Bqm observed below 100 cm in some pedons.

COMPETING SERIES:
Battleax--umbric epipedon
Divers--less than 40 percent sand; no duripan within 200 cm
Highcamp--less than 40 percent sand; no duripan within 200 cm
Holderman--50 to 100 cm (moderately deep) to a restrictive feature
Hummington--50 to 100 cm (moderately deep) to a restrictive feature
Icecap--50 to 100 cm (moderately deep) to a restrictive feature
Idanha--umbric epipedon
Ohana--50 to 100 cm (moderately deep) to a restrictive feature
Otwin--50 to 100 cm (moderately deep) to a restrictive feature

GEOGRAPHIC SETTING:
Elevation--1500 to 2400 m
Slope--0 to 90 percent
Climate--humid, with precipitation occurring mainly in winter and spring
Mean annual precipitation--900 to 1780 mm
Mean annual air temperature--3.9 to 7.0 degrees C
Mean January air temperature--0 to 1.7 degrees C
Frost-free period--10 to 50 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Kyotesue--frigid temperature regime
Llaorock--vitric subgroup
Otwin--50 to 100 cm (moderately deep) to a restrictive feature
Molawa--medial, with less than 35 percent rock fragments
Woodcock--have an argillic horizon, a mollic epipedon, a xeric soil moisture regime and a frigid temperature regime
Pokegema--medial, have a mollic epipedon, a xeric soil moisture regime and a frigid temperature regime

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--Well drained
Saturated hydraulic conductivity (Ksat)--very high in O horizons; high in mineral horizons

USE AND VEGETATION:
Use--Timber production, wildlife habitat, and recreation
Overstory vegetation--white fir, Shasta red fir, western white pine, mountain hemlock, ponderosa pine
Understory vegetation--mountain brome, western princes pine, sedge, pinemat manzanita, grouse whortleberry

DISTRIBUTION AND EXTENT: Cascade Mountains in southern Oregon; MLRA 3; moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Klamath County, Oregon, 1977.

REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--8 to 108 cm
*Ochric epipedon
*Andic soil properties--8 to 208 cm
*Volcanic glass--8 to 208 cm
*Cambic horizon--18 to 114 cm
*Udic soil moisture regime based on correlation to Shasta red fir with white fir plant associations and ecological sites.
*Haplocryand--15 bar dry is more than 15 percent throughout
*Medial--Andic soil properties present throughout the particle-size control section; 15 bar water dry is more than 15 percent throughout
*Amorphic--The particle-size control section has over 2 percent acid oxalate extractable silica

ADDITIONAL DATA:
*NASIS Site ID--1977OR029001
*NASIS Pedon ID--1977OR029001
*Andic soil properties--based on laboratory data from NSSL S01OR-035-002, 003, 004 and 005

11/2010--Type location moved from Klamath County to Jackson County (to the modal pedon for Oatman soil in the Jackson County Soil Survey manuscript), following correlation of the original Oatman type location to a frigid soil temperature regime.

05/2011--Classification changed from Loamy-skeletal, mixed Dystric Cryochrepts to Medial-skeletal, amorphic Typic Haplocryands based on lab data.

06/2017--Updated this official series description according to SSRO1 Technical Note 11, OSD-- and Format of Official Series Descriptions (revised 12/2015). Most of the changes were in formatting.

National Cooperative Soil Survey
U.S.A.