LOCATION UNDERWOOD WA
Established Series
Rev. AG/EH/RWL
09/2019
UNDERWOOD SERIES
Landscape--mountains, plateaus
Landform--mountain slopes, structural benches
Slope--2 to 50 percent
Parent material--residuum and colluvium derived from basalt and andesite mixed with volcanic ash in upper part
Mean annual precipitation--about 1300 mm
Mean annual air temperature--about 8 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--mesic
Soil moisture subclass--typic
TAXONOMIC CLASS: Fine-loamy, isotic, mesic Vitrandic Haploxeralfs
TYPICAL PEDON: Underwood paragravelly ashy loam, forested, on a 14-percent, southeast-facing slope at an elevation of 370 m (All textures are apparent field textures.)
Oi--0 to 3 cm; slightly decomposed needles, leaves, and twigs
Oa--3 to 5 cm; highly decomposed organic material
Ac--5 to 25 cm; paragravelly ashy loam, brown (7.5YR 4/4) dry, dark brown (7.5YR 3/2) moist; weak coarse granular structure; soft, very friable, slightly sticky and nonplastic; weakly smeary; many fine and common medium roots; many coarse irregular pores; 30 percent Fe/Mn concretions (2 to 4 mm in size); slightly acid (pH 6.2); clear smooth boundary
2BA--25 to 53 cm; loam, brown (7.5YR 5/4) dry, dark brown (7.5YR 3/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; common fine and medium roots; many fine irregular pores and few fine tubular pores; few gravel; moderately acid (pH 6.0); clear smooth boundary
2Bt--53 to 94 cm; clay loam, brown (7.5YR 5/4) dry, dark brown (7.5YR 3/4) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and moderately plastic; few fine, medium, and coarse roots; many fine irregular pores and few fine tubular pores; 5 percent paragravel; common distinct clay films in pores and on faces of peds; strongly acid (pH 5.4); clear wavy boundary
2C--94 to 157 cm; paragravelly loam, brownish yellow (10YR 6/6) dry, dark yellowish brown (10YR 4/6) moist; common medium distinct mottles, yellowish red (5YR 4/6) moist or dry; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; common medium irregular and tubular pores; 15 percent paragravel; very strongly acid (pH 5.1)
TYPE LOCATION: Skamania County, Washington, about 1.5 km south of Willard; about 60 m south and 520 m west of the northeast corner of section 11, T. 3 N., R. 9 E.; latitude 45 degrees, 45 minutes, 55 seconds north and longitude 121 degrees, 38 minutes, 8 seconds west
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--8 to 10 degrees C
Moisture control section--dry in all parts 45 to 60 consecutive days during the 4 months following summer solstice in 6 years or more out of 10 years
Thickness of solum--75 to 100 cm
Depth to bedrock--100 cm or more
Particle-size control section--25 to 35 percent clay; averages 5 to 30 percent pararock fragments and 0 to 20 percent gravel and cobbles
Below particle-size control section--0 to 25 percent rock fragments; 0 to 50 percent pararock fragments
Volcanic ash influence
*Thickness--20 to 35 cm
*Moist bulk density--1.1 to 1.3 g/cm3
*Volcanic glass content--5 to 30 percent
*Acid oxalate aluminum plus one-half iron--1 to 2 percent
*Phosphorus retention--50 to 75 percent
*15-bar water retention--8 to 12 percent
Ac horizon
Hue--5YR, 7.5YR
Value--3, 4, or 5 dry, 3 or 4 moist
Chroma--2 to 4 moist, 3 to 6 dry
Fe/Mn concretion content--15 to 30 percent
Reaction--6.1 to 7.3
Thickness--18 to 35 cm
2BA horizon
Thickness--0 to 41 cm
2Bt horizon
Hue--5YR, 7.5YR
Value--3 or 4 moist, 4 or 5 dry
Chroma--4 to 6 dry
Texture--loam, gravelly loam, paragravelly loam, clay loam
Reaction--5.1 to 6.5
Thickness--41 to 117 cm
C horizon
Hue--5YR, 7.5YR, 10YR
Value--4 or 5 moist, 5 or 6 dry
Chroma--4 to 6 dry
Texture--loam, gravelly loam, clay loam, paragravelly loam, very paragravelly loam
Reaction--5.1 to 6.0
COMPETING SERIES:
Bernhill--dry 60 to 90 consecutive days following summer solstice; no pararock fragments
Kramerhill--100 to 150 cm (deep) to a paralithic contact (gneiss); dry 60 to 90 consecutive days following summer solstice
Ulhalf--100 to 150 cm (deep) to a paralithic contact (andesite); dry 105 consecutive days following summer solstice
Wilkeson--150 cm deep or more to base of argillic horizon; no pararock fragments; hue of 2.5Y to 7.5YR in argillic horizon
GEOGRAPHIC SETTING:
Elevation--120 to 850 m
Climate--warm, dry summers; cold, wet winters; intermittent snow cover
Mean annual precipitation--890 to 1650 mm
Mean January air temperature--about -3 degrees C
Mean July air temperature--about 19 degrees C
Mean annual air temperature--7 to 9 degrees C
Frost-free season--100 to 150 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Chemawa--ashy particle-size class; on nearby uplands and mountains
McElroy--skeletal particle-size class; on nearby uplands and mountains
Timberhead--frigid soil temperature regime; ashy particle-size class; on nearby uplands and mountains
Undusk--frigid soil temperature regime; skeletal particle-size class; on nearby uplands and mountains
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--moderately high
USE AND VEGETATION:
Use--timber production, some orchard crop production and homesite development, wildlife habitat, livestock grazing
Native vegetation--Douglas-fir, bigleaf maple, vine maple, salal, starflower, western brackenfern
DISTRIBUTION AND EXTENT: Southeastern Skamania County and western Klickitat County, Washington; MLRA 6; small extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skamania County, Washington; 1947
REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Ochric epipedon
*Argillic horizon--zone from 53 to 94 cm
*Vitrandic subgroup feature--zone from 5 to 25 cm
*Particle-size control section--zone from 53 to 94 cm
National Cooperative Soil Survey
U.S.A.