Targhee National Forest, Idaho and Wyoming
The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). 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 Targhee National Forest, Idaho and Wyoming.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Edgway-Jumpstart-Tophat complex, 15 to 50 percent slopes | 118K | Well drained | C | Very limited | Very limited |
| Juliette-Fritz association, 40 to 70 percent slopes | 99K | Well drained | B | Very limited | Very limited |
| Koffgo-Rhylow-Povey complex, 35 to 60 percent slopes | 90K | Well drained | B | Very limited | Very limited |
| Islandpark-Potrmound-Spliten complex, 0 to 35 percent slopes | 79K | Well drained | B | Not limited | Very limited |
| Gany-Fritz association, 40 to 70 percent slopes | 68K | Well drained | B | Very limited | Very limited |
| Lagall-Povey-Fritz complex, 35 to 70 percent slopes | 64K | Well drained | B | Very limited | Very limited |
| Edgway very gravelly loam, 15 to 40 percent slopes | 61K | Well drained | C | Very limited | Very limited |
| Koffgo-Koffgo, low effective precipitation-Rock outcrop complex, 40 to 70 percent slopes | 60K | Well drained | B | Very limited | Very limited |
| Edgway-Koffgo-Povey association, 15 to 50 percent slopes | 51K | Well drained | B | Very limited | Very limited |
| Flatstone-Koffgo complex, 2 to 15 percent slopes | 43K | Well drained | B | Somewhat limited | Very limited |
| Meegero-Monida complex, 20 to 50 percent slopes | 43K | Well drained | B | Very limited | Very limited |
| Rhylow-Fitzwil association, 4 to 40 percent slopes | 42K | Well drained | A | Very limited | Very limited |
| Huckridge-Koffgo-Povey complex, 4 to 50 percent slopes | 39K | Well drained | B | Very limited | Very limited |
| Koffgo ashy silt loam, 4 to 15 percent slopes | 38K | Well drained | B | Somewhat limited | Very limited |
| Dashiki-Lasac association, 2 to 25 percent slopes | 37K | Well drained | A | Not limited | Very limited |
| Yodal gravelly loam, 35 to 60 percent slopes | 36K | Well drained | B | Very limited | Very limited |
| Lagall very stony ashy loam, 25 to 50 percent slopes | 36K | Well drained | B | Very limited | Very limited |
| Winegar-Bradco complex, 4 to 15 percent slopes | 33K | Well drained | B | Somewhat limited | Somewhat limited |
| Gany-Katpa-Fritz complex, 40 to 70 percent slopes | 32K | Well drained | B | Very limited | Very limited |
| Rubble land-Haplocryepts-Rock outcrop complex, 40 to 70 percent slopes | 31K | A | 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. A geotechnical assessment is recommended before building.
Septic Systems
About 97% 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.