Logan 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 Logan County, Oklahoma.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Coyle-Ironmound complex, 3 to 5 percent slopes, eroded | 28K | Well drained | C | Somewhat limited | Very limited |
| Stephenville-Darnell complex, 5 to 15 percent slopes | 20K | Well drained | C | Somewhat limited | Very limited |
| Ironmound-Coyle complex, 5 to 15 percent slopes | 19K | Well drained | D | Very limited | Very limited |
| Zaneis loam, 3 to 5 percent slopes, moderately eroded | 18K | Well drained | B | Somewhat limited | Somewhat limited |
| Ashport silt loam, 0 to 1 percent slopes, frequently flooded | 18K | Well drained | B | Very limited | Very limited |
| Stephenville-Darnell-Newalla complex, 3 to 8 percent slopes, eroded | 18K | Well drained | C | Somewhat limited | Very limited |
| Grainola silty clay loam, 5 to 8 percent slopes, eroded | 17K | Well drained | D | Very limited | Very limited |
| Darnell-Rock outcrop complex, 8 to 45 percent slopes | 15K | Somewhat excessively drained | D | Very limited | Very limited |
| Masham-Ironmound complex, 5 to 15 percent slopes | 14K | Well drained | D | Very limited | Very limited |
| Renfrow silty clay loam, 3 to 5 percent slopes, eroded | 14K | Well drained | D | Very limited | Very limited |
| Stephenville-Darnell-Newalla complex, 3 to 8 percent slopes | 11K | Well drained | D | Very limited | Very limited |
| Stephenville-Darnell complex, 1 to 5 percent slopes | 11K | Well drained | C | Somewhat limited | Very limited |
| Grainola silty clay loam, 3 to 5 percent slopes | 11K | Well drained | D | Somewhat limited | Very limited |
| Kirkland silty clay loam, 1 to 3 percent slopes | 10K | Well drained | D | Very limited | Very limited |
| Stephenville-Darnell complex, 1 to 5 percent slopes, eroded | 10K | Well drained | C | Somewhat limited | Very limited |
| Coyle loam, 3 to 5 percent slopes, eroded | 9K | Well drained | C | Somewhat limited | Very limited |
| Piedmont silty clay loam, 3 to 5 percent slopes, eroded | 9K | Well drained | D | Very limited | Very limited |
| Pulaski fine sandy loam, 0 to 1 percent slopes, frequently flooded | 9K | Well drained | A | Very limited | Very limited |
| Zaneis loam, 1 to 3 percent slopes | 8K | Well drained | B | Somewhat limited | Somewhat limited |
| Norge silt loam, 3 to 5 percent slopes, eroded | 8K | Well drained | C | Somewhat limited | Very limited |
What This Means
Building & Foundations
About 49% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 90% 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
Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.