LOCATION SOUTHPLATTE CO
Established Series
PRR-KLS-EED
03/2026
SOUTHPLATTE SERIES
Depth class: Very deep
Drainage class: Well drained
Saturated hydraulic conductivity: High (3.6 to 36.0 cm/hr)
Parent material: Thin human-transported material over fine-loamy eolian deposits
Geomorphic location: Fills and other leveled areas on plains mantled with mixed eolian deposits
Slope range: 0 to 3 percent
Mean annual temperature: 11 degrees C
Mean annual precipitation: 405 millimeters
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Haplustepts
TYPICAL PEDON: Southplatte loam, 1 percent slope on a filled plain mantled with mixed eolian deposits under cultivated grasses in a park, at an elevation of 1,604 meters. (Colors are for moist soil unless otherwise noted.)
^A1--0 to 7 centimeters; black (7.5YR 2.5/1) sandy loam; moderate fine granular structure; slightly hard, friable, nonsticky, nonplastic; noneffervescent, neutral (pH 7.2); clear wavy boundary
^A2--7 to 23 centimeters; black (7.5YR 2/1) sandy clay loam; weak fine granular structure, soft, very friable, slightly sticky, nonplastic; noneffervescent; neutral (pH 7.0); gradual wavy boundary (combined thickness of 5 to 20 centimeters)
2Bw--23 to 56 centimeters; dark brown (7.5YR 3/3) sandy clay loam; weak medium subangular block structure; slightly hard, friable, nonsticky, nonplastic; noneffervescent; neutral (pH 7.0); gradual wavy boundary
2BC--56 to 79 centimeters; brown (7.5YR 4/3) sandy loam; weak medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; noneffervescent; neutral (pH 7.0); gradual wavy boundary (combined thickness of B horizons are 15 to 150 centimeters)
2C1--79 to 101 centimeters; brown (7.5YR 4/3) sandy clay loam; massive; moderately hard, firm, moderately sticky, slightly plastic; noneffervescent; neutral (pH 7.0)
2C2--101 to 200 centimeters; brown (10YR 4/3) sandy loam; massive; soft, very friable, nonsticky, nonplastic; noneffervescent; neutral (pH 7.2)
TYPE LOCATION:
Denver County, Colorado; located in the southern section of the northwestern-most couplet of the Park Avenue Parks
USGS Quadrangle: Englewood
Latitude: 39.7464556
Longitude: -104.9771000
Datum: WGS84
Coordinates sources: Hand-held GPS
RANGE IN CHARACTERISTICS:
Thickness of human-transported material: less than 50 centimeters
Depth to bedrock: greater than 150 centimeters
Depth to seasonal high water table: Greater than 200 centimeters
Soil reaction: Neutral to moderately alkaline (pH 7.0 to 8.4)
Depth to free carbonates--25 to 75 centimeters
Particle-size control section (weighted average):
Clay content--18 to 32 percent
Sand content--18 to 45 percent
Rock fragment content--0 to 8 percent
^A(u) horizons:
Hue--7.5YR or 10YR
Value--1 to 5 dry; 1 to 3 moist
Chroma--3 or 4 dry; 1 to 4 moist
Texture (less than 2 mm fraction)--clay loam, loam, sandy clay loam, sandy loam,
Clay content--7 to 30 percent
Rock fragments--0 to 8 percent gravel
Reaction--Neutral to slightly alkaline (pH 7.0 to 8.2)
^C(u) horizons (when present):
Hue--10YR
Value--4 or 5 dry or moist
Chroma--4 or 5 dry or moist
Texture (less than 2 mm fraction)--clay loam, sandy clay loam, sandy loam, silty clay loam
Clay content--25 to 40 percent
Rock fragments--0 to 20 percent gravel
Artifacts--0 to 5 percent
Reaction--Neutral to slightly alkaline (pH 7.2 to 8.2)
Thickness--10 to 25 centimeters
2Bw horizons:
Hue--7.5YR or 10YR
Value--5 or 6 dry; 3 to 4 moist
Chroma--3 or 4 dry; 3 to 5 moist
Texture (less than 2 mm fraction)--clay loam, sandy clay loam, sandy loam, silty clay loam
Clay content--20 to 35 percent
Reaction--Neutral to slightly alkaline (pH 7.0 to 7.8)
2Bk or 2BChorizons (when present):
Hue--7.5YR or 10YR
Value--5 to 7 dry; 3 to 4 moist
Chroma--3 to 5 dry; 3 to 4 moist
Texture (less than 2 mm fraction)--clay loam, sandy clay loam, sandy loam
Clay content--22 to 35 percent
Reaction--Slightly to moderately alkaline (pH 7.0 to 8.2)
2C horizon(s):
Hue--2.5Y or 10YR or 7.5YR
Value--5 or 6 dry; 3 to 6 moist
Chroma--3 to 6 dry; 3 or 5 moist
Texture (less than 2 mm fraction)--clay loam, fine sandy loam, sandy clay loam, sandy loam
Clay content--1 to 35 percent
Reaction--Neutral to moderately alkaline (pH 7.0 to 8.2)
COMPETING SERIES:
These are the
Atchison,
Berthoud,
Kachina, McRae,
Sixmile,
Teromote, and
Ziggy soils. None of these series have human-transported materials in the soil profile.
Atchison soils have concretions of calcium carbonate and iron-manganese in the B horizons and are strongly to violently effervescent with HCl.
Berthoud soils formed in alluvium or colluvium, have concretions of calcium carbonate throughout, and are strongly to violently effervescent with HCl.
Kachina and
Teromote soils formed in alluvium and are driest in the soil moisture control section from
May through June.
McRae soils formed in alluvium and have clay films and prismatic structure in the B horizon.
Sixmile soils have paralithic contacts between 50 and 100 centimeters and have redder hues throughout.
Ziggy soils formed in alluvium, have prismatic structure in the B horizons, have cooler soil temperatures, and range from 105 to 130 frost free days.
GEOGRAPHIC SETTING:
Parent material--Thin human-transported material over fine-loamy eolian deposits Landform: Fills and other leveled areas on plains mantled with mixed eolian deposits
Slope ranges--0 to 3 percent
Mean annual air temperature--10 to 12 degrees C
Mean annual precipitation range--356 to 432 millimeters
Frost-free period--135 to 165 days
Elevation--1,580 to 1,720 meters
Climate: Cold, dry winters and hot summers with North American monsoon precipitation from July through August. The driest months are December through February.
GEOGRAPHICALLY ASSOCIATED SOILS:
These are the
Globeville,
Greenvalley, and
Racas soils.
Globeville soils are found in similar landscape positions, have a fine-loamy particle-size control section, have greater than 50 centimeters of human-transported materials, and lack cambic horizons.
Greenvalley soils are found on nearby filled dunes and sandsheets, and have a coarse-loamy particle-size control section and greater than 50 centimeters of human-transported materials.
Racas soils are found on adjacent filled loess-mantled plains and have greater than 50 centimeters of human-transported materials and a fine particle-size control section.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: Well drained
Saturated hydraulic conductivity: High (3.6 to 36.0 cm/hr)
Flooding: None
Ponding: None
USE AND VEGETATION:
Most areas are primarily used for urban development. Vegetation may include a mix of managed and unmanaged plant communities with a mix of native and non-native species. Many areas are vegetated with non-native ornamental landscaping and/or turfgrass associated with developed land uses. Some areas may exhibit weedy, invasive, and/or primary succession vegetation communities (e.g., abandoned lots and other unmanaged areas). The potential native vegetation is fourwing saltbush, winterfat, western wheatgrass, and blue grama.
DISTRIBUTION AND EXTENT:
Urban and other areas with human-modified landscapes on filled plains, strath terraces, and pediments in the vicinity of Denver in north-central Colorado. MLRA 67B - Central High Plains, Southern Part. These soils are of small extent.
SOIL SURVEY REGION (SSR) RESPONSIBLE: Raleigh, North Carolina (Special Projects Office)
SERIES ESTABLISHED: Denver County, CO 2025.
REMARKS:
Typical Pedon Taxonomic Features:
Ochric epipedon--The zone from 0 to 23 centimeters (^A horizons)
Human-transported materials--The zone from 0 to 23 centimeters (^A horizons)
Lithologic discontinuity--At a depth of 23 centimeters
Cambic horizon--The zone from 23 to 56 centimeters (2Bwb horizon)
Particle-size control section--The zone from 25 to 100 centimeters
Taxonomic version: Keys to Soil Taxonomy, 13th edition, (2022)
Other: The Southplatte name is based on the name of the river that flows through Denver, Colorado. Some Southplatte pedons have a thin surface mantle of human-transported materials and are included in this concept as interpretations or classification are not affected.
ADDITIONAL DATA:
NASIS User Pedon ID: 2020CO031941
National Cooperative Soil Survey
U.S.A.