Harmon County, Oklahoma
The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). 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 Harmon County, Oklahoma.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Tilvern clay loam, 1 to 3 percent slopes | 22K | Well drained | D | Very limited | Very limited |
| Westill clay loam, 1 to 3 percent slopes | 22K | Well drained | D | Very limited | Very limited |
| Woodward-Quinlan complex, 5 to 12 percent slopes | 19K | Well drained | C | Somewhat limited | Very limited |
| Vernon-Knoco complex, cool, 1 to 12 percent slopes | 18K | Well drained | D | Somewhat limited | Very limited |
| Grandfield loamy sand, 0 to 3 percent slopes | 15K | Well drained | B | Not limited | Very limited |
| Aspermont silt loam, 1 to 3 percent slopes | 14K | Well drained | B | Not limited | Somewhat limited |
| Knoco, Rock outcrop, and Cottonwood soils, 2 to 20 percent slopes | 14K | Well drained | D | Very limited | Very limited |
| Knoco-Badland complex, dry, 1 to 12 percent slopes | 11K | Well drained | D | Very limited | Very limited |
| Madge loam, 1 to 3 percent slopes | 11K | Well drained | B | Not limited | Very limited |
| Springer and Devol loamy sands, 0 to 3 percent slopes | 9K | Well drained | A | Not limited | Very limited |
| Tipton loam, 0 to 1 percent slopes | 9K | Well drained | B | Somewhat limited | Somewhat limited |
| Woodward-Quinlan complex, 3 to 5 percent slopes | 8K | Well drained | C | Somewhat limited | Very limited |
| Talpa-Aspermont-Rock outcrop complex, 1 to 8 percent slopes | 8K | Well drained | D | Very limited | Very limited |
| Westill clay loam, 0 to 1 percent slopes | 7K | Well drained | D | Very limited | Very limited |
| Devol and Springer loamy sands, 3 to 8 percent slopes | 6K | Well drained | A | Not limited | Very limited |
| Quinlan-Rock outcrop complex, 12 to 45 percent slopes | 6K | Well drained | D | Very limited | Very limited |
| Vernon clay loam, 3 to 5 percent slopes, eroded | 6K | Well drained | D | Very limited | Very limited |
| Water | 6K | D | Not rated | Not rated | |
| La Casa silty clay loam, 1 to 3 percent slopes | 5K | Well drained | C | Somewhat limited | Very limited |
| Hardeman-Southside-Arnett complex, 3 to 20 percent slopes | 5K | Well drained | A | Somewhat limited | Very limited |
What This Means
Building & Foundations
About 43% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
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.