LOCATION DENOGA OR
Tentative Series
IRD. AGG/KLM/MPR
07/2026
DENOGA SERIES
Landscape--Eastern Cascade mountains
Landform--Lava flows, lava plains, mountain slopes
Slope--0 to 50 percent
Parent Material--Volcanic ash mixed with colluvium and/or residuum weathered from basalt, andesite, or other hard extrusive volcanic rock over bedrock
Mean annual precipitation--700 millimeters
Mean annual air temperature--6 degrees C
Depth class--Deep and very deep to bedrock
Drainage class--Well drained
Soil moisture regime--Xeric
Soil temperature regime--Frigid
Soil moisture subclass--Typic
TAXONOMIC CLASS: Ashy, glassy, frigid Humic Vitrixerands
TYPICAL PEDON: Denoga ashy sandy loam, forested, on a northeast-facing mountain slope, at an elevation of 1390 meters. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 2 centimeters; slightly decomposed plant material; strongly acid (pH 5.5); abrupt smooth boundary
A1--2 to 12 centimeters; ashy sandy loam, dark grayish brown (10YR 4/2), black (10YR 2/1), moist; moderate medium granular structure; soft, very friable, nonsticky, nonplastic; few very fine and fine roots; many fine irregular pores; 5 percent gravel; neutral (pH 6.8); clear smooth boundary
A2--12 to 67 centimeters; ashy sandy loam, dark grayish brown (10YR 4/2), very dark brown (10YR 2/2), moist; moderate medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; common medium and few fine roots; many fine irregular pores; 10 percent gravel; neutral (pH 6.9); gradual smooth boundary
Bw--67 to 96 centimeters; gravelly ashy sandy loam, yellowish brown (10YR 5/4), dark brown (10YR 3/3), moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; common medium and few fine and coarse roots; many medium irregular and many fine tubular pores; 25 percent gravel; neutral (pH 7.0); gradual smooth boundary
C--96 to 112 centimeters; very gravelly ashy sandy loam, yellowish brown (10YR 5/4), dark brown (10YR 3/3), moist; structureless single grain; soft, very friable, nonsticky, nonplastic; very few fine roots; common fine tubular pores; 40 percent gravel; neutral (pH 7.0)
2R--112 centimeters; basalt bedrock
TYPE LOCATION: Deschutes County, Oregon
USGS Quadrangle: Black Crater, OR
Latitude: 44.2909880
Longitude: -121.7141660
Datum WGS84
Coordinates source: Hand-held GPS
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--around 7 degrees C
Soil Moisture--usually moist in winter and spring, dry in the moisture control section for 60 to 90 days in the 4 months following the summer solstice
Thickness of mollic epipedon--25 to 70 centimeters
Thickness of cambic horizon--30 to 85 centimeters
Depth to lithic contact--between 100 and 200 centimeters
Reaction--pH 6.1 to 7.3 (slightly acid to neutral)
Thickness of ash influenced layers--100 to 200 centimeters
Estimated properties of layers influenced by volcanic ash:
Ammonium oxalate extractable Al + Fe--0.4 to 1.0 percent
1500 kPa water content (air dry)--less than 15 percent
0.02 to 2.0 mm fraction--50 to 90 percent
Volcanic glass in the 0.02 to 2.0 millimeter fraction--50 to 80 percent
P retention--40 to 70 percent
Particle-size control section: mineral surface to 100 centimeters
Clay content (weighted average): 2 to 8 percent
Rock fragment content (weighted average): 0 to 35 percent
O horizon:
Thickness--0 to 5 centimeters
A horizons
Value--2 moist, 3 or 4 dry
Chroma--1 or 2
Fine earth texture--ashy sandy loam, ashy loamy sand
Clay--2 to 8 percent
Sand--60 to 85 percent
Organic matter--1 to 5 percent
Total rock fragment content--0 to 10 percent
Gravel--0 to 10 percent
Pumice paragravel--0 to 5 percent
Reaction--6.1 to 7.3 (slightly acid to neutral)
Thickness--combined thickness of A horizons is 15 to 65 centimeters
Bw horizon
Value--2 to 4 moist, 4 to 5 dry
Chroma--2 to 4 moist, 2 to 6 dry
Fine earth texture--ashy sandy loam, ashy loamy sand
Clay--1 to 8 percent
Sand--65 to 90 percent
Organic matter--0.5 to 1 percent
Total rock fragment content--0 to 35 percent
Gravel--0 to 35 percent
Pumice paragravel--0 to 10 percent
Cobble--0 to 20 percent
Stone--0 to 10 percent
Reaction--6.1 to 7.3 (slightly acid to neutral)
Thickness--Thickness of B horizon is 25 to 60 centimeters
C horizon
Value--2 to 4 moist, 4 or 5 dry
Chroma--2 to 4 moist, 3 to 6 dry
Fine earth texture--ashy sandy loam, ashy loamy sand, ashy coarse sand
Clay--1 to 8 percent
Sand--65 to 95 percent
Organic matter--0.1 to 0.5 percent
Total rock fragment content--10 to 85 percent
Gravel--10 to 60 percent
Pumice paragravel--0 to 10 percent
Cobble--0 to 40 percent
Stone--0 to 20 percent
Reaction--6.1 to 7.3 (slightly acid to neutral)
Thickness--Thickness of C horizon is 15 to 50 centimeters
COMPETING SERIES:
Cobey--Averages less than 50 percent sand throughout the particle size control section (loam and silt loam texture classes)
Conelicker--Gravel sized cinders throughout the particle size control section; depth to bedrock greater than 150 centimeters
Dryache--Dry for 45 to 60 days following the summer solstice
Drypok--50 to 100 cm to lithic contact
Ermabell--Dry for 90 to 110 days following summer solstice; depth to bedrock greater than 150 centimeters
Laidlaw--Dry for 90 to 110 days following summer solstice; has silica nodules in the lower horizons; depth to bedrock greater than 150 centimeters
Lundgren--Depth to bedrock greater than 150 centimeters
Pilotbutte--Depth to bedrock greater than 150 centimeters
Retep--50 to 100 centimeters to a paralithic contact
Spodue--Depth to bedrock greater than 150 centimeters
Suttle--Endosaturation from 0 to 60 cm April to June (somewhat poorly drained)
Trailcreek--50 to 100 centimeters to a paralithic contact
Wanoga--50 to 100 centimeters to a lithic contact
GEOGRAPHIC SETTING:
Elevation--950 to 1700 meters
Slope--0 to 50 percent
Climate--cool, wet winters and warm, dry summers
Mean annual precipitation--400 to 1000 millimeters
Mean annual air temperature--5 to 7 degrees C
Frost-free period--50 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Skelwa--Occurs on nearby outwash plains; greater than 35 percent fragments in the particle size control section
Wanoga--Occurs on similar geomorphic positions; 50 to 100 centimeters to a paralithic or lithic contact; 90 to 110 dry days following the summer solstice
Fryrear--Occurs on similar geomorphic positions; 50 to 100 centimeters to a paralithic or lithic contact; greater than 35 percent fragments in the particle size control section
Dryache--Occurs at higher elevations on moraines; 45 to 60 dry days following the summer solstice
Sanagon--Occurs at higher elevations on moraines; 45 to 60 dry days following the summer solstice; greater than 35 percent fragments in the particle size control section
Laidlaw--Occurs on swales; dry for 90 to 110 days following the summer solstice
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--Well drained
Saturated hydraulic conductivity (Ksat)--High to very high in all horizons
Ponding: None
Flooding: None
USE AND VEGETATION:
Use--Timber production, wildlife habitat, recreation
Vegetation--western juniper, ponderosa pine, antelope bitterbrush, greenleaf manzanita, Idaho fescue, Ross' sedge; where precipitation is above 510 mm Douglas-fir, grand fir, white fir, pinegrass, pipsissewa, long-stolon sedge, snowbrush ceanothus, golden chinkapin
Typical USFS plant association--ABCO-ABGR/CAIN4 (white fir-grand fir/long-stolon sedge)
DISTRIBUTION AND EXTENT:
East slope of the Cascade Mountains in central Oregon; MLRA 6; minor extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED:
Deschutes County, Deschutes National Forest, Oregon 2023
REMARKS:
Typical Pedon Taxonomic Features::
Particle-size control section--2 to 102 centimeters
Mollic epipedon--2 to 67 centimeters
Andic soil properties--2 to 112 centimeters
Cambic horizon--67 to 96 centimeters
Andic soil properties--2 to 112 centimeters
Lithic contact--112 centimeters
Taxonomic version: Keys to Soil Taxonomy, 13th edition (2022)
Laboratory data inferred from geographically associated Laidlaw series (Pedon#: 23NO202). This data is available from the NRCS-NSSC-Kellogg Soil Survey Laboratory, Lincoln, Nebraska.
National Cooperative Soil Survey
U.S.A.