Oglala Lakota County Area, South Dakota
The most common soil here is Canyon, on about 13% of the land: a loam, a balanced mix that crumbles in your hand. Oglala and Keith come next.
About 98% of the land drains well.
USDA rates 87% of the land very limited for a standard septic drain field, and 69% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 8% of the land floods occasionally or more, and bedrock lies within 40 inches under 61% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Oglala Lakota County Area, South Dakota, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Oglala Lakota County Area, South Dakota. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Oglala-Canyon loams, 9 to 25 percent slopes | 141K | Well drained | B | Very limited | Very limited |
| Canyon-Rock outcrop association, 18 to 40 percent slopes | 117K | Well drained | D | Very limited | Very limited |
| Canyon-Oglala loams, 18 to 40 percent slopes | 72K | Well drained | D | Very limited | Very limited |
| Pierre silty clay, 6 to 25 percent slopes | 55K | Well drained | D | Very limited | Very limited |
| Badland-Denby-Interior complex, 0 to 90 percent slopes | 48K | Well drained | Very limited | Very limited | |
| Lohmiller silty clay loam, channeled, 0 to 2 percent slopes | 42K | Well drained | C | Very limited | Very limited |
| Keith-Colby silt loams, 9 to 12 percent slopes | 41K | Well drained | B | Somewhat limited | Somewhat limited |
| Epping-Kadoka silt loams, 9 to 18 percent slopes | 36K | Well drained | D | Very limited | Very limited |
| Badland | 35K | Excessively drained | D | Very limited | Very limited |
| Rosebud-Canyon loams, 5 to 9 percent slopes | 31K | Well drained | C | Somewhat limited | Very limited |
| Valentine sand, 3 to 30 percent slopes | 30K | Excessively drained | A | Very limited | Very limited |
| Denby silty clay, 0 to 3 percent slopes | 28K | Well drained | C | Somewhat limited | Very limited |
| Keith-Colby silt loams, 12 to 25 percent slopes | 27K | Well drained | B | Very limited | Very limited |
| Anselmo-Valentine complex, 5 to 20 percent slopes | 26K | Well drained | A | Somewhat limited | Very limited |
| Keith silt loam, 0 to 3 percent slopes | 26K | Well drained | B | Not limited | Somewhat limited |
| Interior silt loam, 0 to 3 percent slopes | 24K | Well drained | B | Very limited | Very limited |
| Pierre clay, 3 to 9 percent slopes | 23K | Well drained | D | Very limited | Very limited |
| Wortman-Wanblee silt loams, 0 to 6 percent slopes | 21K | Well drained | D | Somewhat limited | Very limited |
| Rosebud-Keith silt loams, 3 to 9 percent slopes | 20K | Well drained | C | Somewhat limited | Very limited |
| Epping-Badland complex, 3 to 60 percent slopes | 19K | Somewhat excessively drained | D | Very limited | Very limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 69% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 87% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.