Kootenai National Forest Area, Montana-Idaho
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 Kootenai National Forest Area, Montana-Idaho.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Andic Dystrochrepts, glaciated mountain slopes | 475K | Well drained | B | Very limited | Very limited |
| Andic Dystrochrepts-Rock outcrop complex, glaciated mountain slopes | 437K | Well drained | B | Very limited | Very limited |
| Phillcher-Rock outcrop complex, mountain slopes | 102K | Well drained | B | Very limited | Very limited |
| Phillcher ashy silt loam, glaciated mountain ridges | 100K | Well drained | B | Very limited | Very limited |
| Rock outcrop-Andic Cryochrepts-Lithic Cryochrepts complex, glacial trough walls | 91K | Well drained | D | Very limited | Very limited |
| Lithic Cryochrepts-Andic Cryochrepts-Rock outcrop complex, glaciated mountain ridges | 91K | Well drained | D | Very limited | Very limited |
| Andic Dystrochrepts, breaklands | 76K | Well drained | B | Very limited | Very limited |
| Eutric Glossoboralfs, moraines | 69K | Well drained | C | Very limited | Very limited |
| Phillcher-Rock Outcrop-Sig complex, dissected glaciated mountain slopes | 69K | Well drained | B | Very limited | Very limited |
| Andic Dystric Eutrochrepts, lacustrine terraces-Andic Dystrochrepts, glacial outwash terraces, complex | 60K | Moderately well drained | B | Not limited | Somewhat limited |
| Rock outcrop-Lithic Cryochrepts-Andic Cryochrepts complex, cirque headwalls and alpine ridges | 60K | D | Not rated | Not rated | |
| Andic Dystrochrepts, mountain slopes | 58K | Well drained | B | Very limited | Very limited |
| Andic Cryochrepts-Rock outcrop-Lithic Cryochrepts complex, glaciated mountain ridges | 58K | Well drained | D | Very limited | Very limited |
| Andic Dystric Eutrochrepts, lacustrine terraces | 51K | Moderately well drained | B | Not limited | Somewhat limited |
| Andic Cryochrepts, moraines, steep | 51K | Well drained | B | Very limited | Very limited |
| Andic Cryochrepts, moraines, dense, brittle substratum | 50K | Well drained | B | Very limited | Very limited |
| Rock outcrop-Lithic Ustochrepts-Typic Ustochrepts complex, breaklands | 46K | Well drained | D | Very limited | Very limited |
| Andic Cryochrepts, moraines | 45K | Well drained | B | Very limited | Very limited |
| Typic Eutroboralfs, moraines | 44K | Well drained | C | Very limited | Very limited |
| Typic Ustochrepts, glaciated mountain slopes, steep | 40K | Well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 91% 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 91% 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.