LOCATION CALIMUS OR+CA
Established Series
Rev. JSC/AON/TDT/BTH/CEG
09/2025
CALIMUS SERIES
Landscape--intermontane basins
Landform--steep lake terraces, terrace escarpments, and alluvial fans
Slope--0 to 35 percent
Parent material--alluvium and slope alluvium derived from interbedded diatomaceous siltstones and sandstones, tuff, and basalt
Mean annual precipitation--about 305 mm
Mean annual air temperature--about 9 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--aridic
Soil temperature regime--mesic
Soil moisture subclass--xeric
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Pachic Haploxerolls
TYPICAL PEDON: Calimus loam, cultivated land, on a northeast-facing (45 degree) terrace with a 2 percent slope at 1269 m elevation.
Ap--0 to 20 cm; loam, dark gray (10YR 4/1) dry, very dark brown (10YR 2/2) moist; weak fine platy and weak very fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; neutral (pH 7.0); abrupt smooth boundary.
A--20 to 36 cm; loam, dark gray (10YR 4/1) dry, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; neutral (pH 6.8); gradual smooth boundary.
AB--36 to 56 cm; loam, dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; neutral (pH 6.8); gradual smooth boundary.
Bw1--56 to 109 cm; loam, dark grayish brown (10YR 4/2) dry, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; neutral (pH 6.9); gradual smooth boundary.
Bw2--109 to 122 cm; loam, dark grayish brown (10YR 4/2) dry, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common fine and very fine tubular pores; neutral (pH 7.1); gradual smooth boundary.
C--122 to 200 cm; loam, brown (10YR 5/3) dry, dark brown (10YR 3/3) moist; massive; very friable, slightly sticky and slightly plastic; common very fine roots; common very fine pores; neutral (pH 7.1).
TYPE LOCATION: Klamath County, Oregon; about 18 km south and 8 km west of Klamath Falls, about 400 m east and 300 m south of the NW corner of sec. 27, T. 40 S., R. 8E., Willamette Meridian; Worden, Oregon USGS quadrangle; latitude 42.0653917 degrees north, longitude 121.8705222 degrees west, datum WGS84 (coordinates derived from topographic map legal description)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--8 to 12 degrees C
Moisture control section--10 to 30 cm; dry for 90 or more consecutive days from April 1 to October 1
Thickness of mollic epipedon--50 to 75 cm
Mollic colors typically extend deeper than the mollic epipedon but organic matter content is less than 1 percent. Depth to the C horizon is 75 to 125 cm. Some pedons are calcareous below 100 cm.
Particle-size control section
*Clay content--18 to 30 percent
*Fine sand or coarser content--30 to 50 percent
*Rock fragment content--0 to 10 percent; predominantly fine gravels
A or AB horizons
Value--4 or 5 dry, 2 or 3 moist
Chroma--1 or 2, dry or moist
Fine-earth texture--fine sandy loam, loam, clay loam, silt loam
Clay content--15 to 30 percent
Rock fragment content--0 to 10 percent gravel
Reaction--slightly acid to slightly alkaline (pH 6.1 to 7.8)
Thickness--10 to 25 cm
Bw horizons (or Bt horizon(s), where present)
Hue--10YR, 7.5YR
Value--4 to 6 dry, 2 to 4 moist
Chroma--1 to 3, dry or moist
Fine-earth texture--loam, silt loam, clay loam, sandy clay loam
Clay content--18 to 30 percent
Rock fragment content--0 to 10 percent gravel
Reaction--slightly acid to slightly alkaline (pH 6.1 to 7.8)
Structure--weak or moderate subangular blocky
Thickness--25 to 60 cm
C horizons
Value--4 to 6 dry, 3 or 4 moist
Chroma--2 to 4, dry or moist
Fine-earth texture--loam, silt loam, sandy loam, loamy sand, loamy fine sand
Clay content--8 to 22 percent
Rock fragment content--typically less than 15 percent gravel; may contain thin strata with up to 60 percent gravel
Reaction--slightly acid to moderately alkaline (pH 6.1 to 8.4)
COMPETING SERIES:
Alicel--typic xeric moisture regime; lithologic discontinuity; moisture control section dry in all parts for 60 to 80 consecutive days
Chalkford--typic xeric moisture regime; redoximorphic features at depths below 90-150 cm (somewhat poorly drained)
Jamescanny--greater than 15 percent rock fragments in the particle size control section; redoximorphic features at depths below 100 cm (moderately well drained)
Linville--typic xeric moisture regime; moisture control section dry in all parts for 75 to 90 consecutive days in summer and fall
Sinamox--silt loam textures in A horizons; clay loam or silty clay loam substratum; 100 to more than 150 cm to paralithic contact
Sweeney--typic xeric moisture regime; moisture control section dry for more than 60 consecutive days
Watama--typic xeric moisture regime; moisture control section dry for more than 60 consecutive days
GEOGRAPHIC SETTING:
Elevation--1220 to 1500 m
Climate--hot, dry summers and cool, moist winters
Mean annual air temperature--7 to 11 degrees C
Mean January temperature-- -3 to -2 degrees C
Mean July temperature--18 to 21 degrees C
Mean annual precipitation--250 to 560 mm
Frost-free period--50 to 120 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Capona--on plateaus, structural benches, and rock pediments; 50 to 100 cm to bedrock (moderately deep)
Henley--on terraces; strongly or very strongly alkaline (pH 8.5 or greater); 50 to 100 cm to duripan (moderately deep)
Laki--on terraces; moderately well drained; calcareous
Lorella--on hills, mountains, escarpments, and structural benches; 25 to 50 cm to bedrock (shallow)
Stukel--on hills, lava plains, and rock benches; 25 to 50 cm to bedrock (shallow)
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--moderately high to high in the A and Bw, Bt horizons; moderately high to very high in C horizons
USE AND VEGETATION:
Use--irrigated and dryland crops, livestock grazing, homesites; steep slopes used for range
Vegetation--big sagebrush, other shrubs, bunchgrasses
DISTRIBUTION AND EXTENT: Klamath and Shasta Valleys and Basins, lake basins in south-central Oregon and northern California; MLRA 21; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Modoc County, near Alturas, California; 1974
REMARKS:
Diagnostic horizons and features in this pedon
*Particle-size control section--zone from 25 to 100 cm
*Mollic epipedon--Ap, A, AB horizons
*Cambic horizon--Bw1, Bw2 horizons
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.
03/2025--This official series description was updated according to SSRO1 Technical Note-Content and Format of Official Series Descriptions (revised 11/6/2017); most of the changes were in formatting with a few technical updates in expanded range of characteristics, landforms, and parent material description.
ADDITIONAL DATA:
NASIS SITE ID--1977OR035015
NASIS PEDON ID--1977OR035015
Characterization data on two profiles (S67 Ore. 18-1 and 18-4) reported in Riverside Soil Survey Laboratory report for Calimus soils sampled in Klamath County, Oregon, 1967.
National Cooperative Soil Survey
U.S.A.