Big Horn National Forest, Wyoming, Parts of Big Horn, Johnson, Sheridan, and Washakie Counties
The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate 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 Big Horn National Forest, Wyoming, Parts of Big Horn, Johnson, Sheridan, and Washakie Counties.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Agneston-Granile-Rock outcrop association, 5 to 50 percent slopes | 144K | Well drained | C | Very limited | Very limited |
| Cloud Peak gravelly silt loam, 5 to 45 percent slopes | 107K | Well drained | C | Very limited | Very limited |
| Tellman-Granile-Agneston association, 2 to 20 percent slopes | 95K | Well drained | C | Very limited | Very limited |
| Rock outcrop-Teewinot-Agneston association, 5 to 35 percent slopes | 76K | Well drained | D | Very limited | Very limited |
| Frisco-Troutville association, 2 to 40 percent slopes, extremely stony | 68K | Well drained | B | Very limited | Very limited |
| Nathrop-Passcreek-Starley association, 2 to 30 percent slopes | 59K | Well drained | C | Very limited | Very limited |
| Agneston-Leighcan-Rock outcrop complex, 5 to 30 percent slopes | 57K | Well drained | C | Very limited | Very limited |
| Rock outcrop-Mirror-Teewinot association, 5 to 35 percent slopes | 48K | D | Not rated | Not rated | |
| Owen Creek-Echemoor-Bynum association, 2 to 30 percent slopes | 45K | Well drained | D | Very limited | Very limited |
| Rock outcrop-Agneston-Rubble land association, 5 to 60 percent slopes | 41K | D | Not rated | Not rated | |
| Tongue River-Gateway association, 2 to 35 percent slopes | 40K | Well drained | C | Very limited | Very limited |
| Rubble land, 5 to 50 percent slopes | 40K | A | Not rated | Not rated | |
| Rock outcrop-Cloud Peak association, 10 to 70 percent slopes | 37K | D | Not rated | Not rated | |
| Starman-Starley association, 2 to 30 percent slopes | 32K | Well drained | D | Very limited | Very limited |
| Lucky-Burgess-Hazton association, 2 to 30 percent slopes | 28K | Well drained | C | Very limited | Very limited |
| Cloud Peak-Fine, mixed, superactive ustic haplocryalfs-Fine-loamy, mixed, superactive lithic argicryolls, association, 10 to 65 percent slopes | 27K | Well drained | D | Very limited | Very limited |
| Cirque land, 10 to 130 percent slopes | 27K | Not rated | Not rated | ||
| Owen Creek-Waybe association, 5 to 35 percent slopes | 26K | Well drained | D | Very limited | Very limited |
| Fourmile loam, 2 to 30 percent slopes | 16K | Well drained | C | Somewhat limited | Very limited |
| Cryaquolls, 0 to 5 percent slopes | 14K | Very poorly drained | B/D | Very limited | Very limited |
What This Means
Building & Foundations
About 79% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 81% 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.