Upper Flathead Valley Area, Montana
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 Upper Flathead Valley Area, Montana.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Water | 11K | Not rated | Not rated | ||
| Waits and Krause stony loams, 12 to 40 percent slopes | 9K | Well drained | B | Very limited | Very limited |
| Alluvial land, poorly drained | 9K | Poorly drained | C | Very limited | Very limited |
| Swims silty clay loam, 0 to 4 percent slopes | 9K | Moderately well drained | A | Somewhat limited | Very limited |
| Creston silt loam, 0 to 3 percent slopes | 8K | Well drained | B | Somewhat limited | Somewhat limited |
| Kalispell loam, 0 to 3 percent slopes | 6K | Well drained | B | Not limited | Somewhat limited |
| Half Moon silt loam, 0 to 3 percent slopes | 6K | Well drained | C | Not limited | Very limited |
| Mountainous land | 5K | Well drained | B | Very limited | Very limited |
| Whitefish stony silt loam, 20 to 45 percent slopes | 5K | Well drained | C | Very limited | Very limited |
| Depew silty clay loam, 0 to 3 percent slopes | 5K | Moderately well drained | C | Very limited | Very limited |
| Whitefish cobbly silt loam, 7 to 12 percent slopes | 5K | Well drained | C | Somewhat limited | Very limited |
| Whitefish cobbly silt loam, 12 to 20 percent slopes | 5K | Well drained | C | Very limited | Very limited |
| Muck and peat | 4K | Very poorly drained | A/D | Very limited | Very limited |
| Mires gravelly loam, 0 to 3 percent slopes | 4K | Well drained | B | Not limited | Very limited |
| Chamokane soils, 0 to 3 percent slopes | 4K | Moderately well drained | B | Very limited | Very limited |
| Half Moon very fine sandy loam, 0 to 3 percent slopes | 4K | Well drained | C | Not limited | Very limited |
| Somers silty clay loam, 0 to 3 percent slopes | 3K | Moderately well drained | C | Somewhat limited | Very limited |
| Whitefish cobbly silt loam, 0 to 7 percent slopes | 3K | Well drained | C | Not limited | Very limited |
| Waits stony silt loam, 7 to 12 percent slopes | 3K | Well drained | B | Somewhat limited | Somewhat limited |
| Blanchard loamy fine sand, 3 to 7 percent slopes | 3K | Excessively drained | A | Not limited | Very limited |
What This Means
Building & Foundations
About 41% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 74% 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.