Marshall County, South Dakota
The most common soil here is Forman, on about 18% of the land: a clay loam, firm and a little sticky. Aastad and Beotia come next.
About 63% of the land drains well, and 21% stays wet for long stretches; groundwater comes within two feet of the surface under 17% of it.
USDA rates 88% of the land very limited for a standard septic drain field, and 29% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 5% of the land floods occasionally or more.
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 Marshall County, 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 C (slow infiltration, moderate 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 Marshall County, 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 |
|---|---|---|---|---|---|
| Forman-Aastad loams, 9 to 15 percent slopes | 47K | Well drained | C | Somewhat limited | Very limited |
| Forman-Aastad loams, 6 to 9 percent slopes | 37K | Well drained | C | Somewhat limited | Very limited |
| Forman-Aastad loams, 1 to 6 percent slopes | 27K | Well drained | C | Somewhat limited | Very limited |
| Beotia silt loam, 0 to 2 percent slopes | 25K | Well drained | B | Somewhat limited | Somewhat limited |
| Harmony-Aberdeen silty clay loams, 0 to 2 percent slopes | 23K | Moderately well drained | C | Somewhat limited | Very limited |
| Water | 20K | Not rated | Not rated | ||
| Southam silty clay loam, 0 to 1 percent slopes | 20K | Very poorly drained | C/D | Very limited | Very limited |
| Beotia-Bearden silt loams, 0 to 2 percent slopes | 18K | Well drained | B | Somewhat limited | Very limited |
| Forman-Buse loams, 15 to 25 percent slopes | 18K | Well drained | C | Very limited | Very limited |
| Nahon-Aberdeen-Exline silt loams, 0 to 2 percent slopes | 14K | Moderately well drained | C | Somewhat limited | Very limited |
| Kranzburg-Brookings silt loams, 0 to 2 percent slopes | 13K | Well drained | C | Somewhat limited | Very limited |
| Buse-Forman loams, 9 to 21 percent slopes | 10K | Well drained | C | Very limited | Very limited |
| Poinsett-Forman complex, 2 to 6 percent slopes | 9K | Well drained | C | Somewhat limited | Very limited |
| Forman-Poinsett complex, 6 to 9 percent slopes | 9K | Well drained | C | Somewhat limited | Very limited |
| Ulen fine sandy loam, 0 to 2 percent slopes | 9K | Somewhat poorly drained | B | Somewhat limited | Very limited |
| Bearden silt loam, 0 to 2 percent slopes | 9K | Somewhat poorly drained | C | Very limited | Very limited |
| Kranzburg-Brookings silt loams, 2 to 6 percent slopes | 8K | Well drained | C | Somewhat limited | Very limited |
| Forman-Poinsett complex, 9 to 15 percent slopes | 8K | Well drained | C | Somewhat limited | Very limited |
| Exline-Aberdeen-Nahon silt loams, 0 to 2 percent slopes | 6K | Somewhat poorly drained | D | Very limited | Very limited |
| Peever clay loam, 2 to 6 percent slopes | 6K | 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 29% 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
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.