Logan County, Oklahoma
The most common soil here is Stephenville, on about 10% of the land: a fine sand, loose sand that holds almost no water. Coyle and Grainola come next.
About 95% of the land drains well.
USDA rates 88% of the land very limited for a standard septic drain field, and 47% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 14% of the land floods occasionally or more, and bedrock lies within 40 inches under 49% 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 Logan County, Oklahoma, 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 Logan County, Oklahoma. 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 |
|---|---|---|---|---|---|
| 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 |
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 47% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 88% 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.