Missoula County Area, Montana
The dominant drainage class is Somewhat excessively 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 Missoula County Area, Montana.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Winkler-Kadygulch family, complex, 30 to 60 percent slopes | 96K | Somewhat excessively drained | B | Very limited | Very limited |
| Winkler very gravelly sandy loam, 30 to 60 percent slopes | 86K | Somewhat excessively drained | A | Very limited | Very limited |
| Holloway gravelly ashy silt loam, 30 to 60 percent slopes | 58K | Somewhat excessively drained | B | Very limited | Very limited |
| Waldbillig-Holloway gravelly ashy silt loams, 30 to 60 percent slopes | 44K | Well drained | B | Very limited | Very limited |
| Waldbillig gravelly silt loam, 4 to 30 percent slopes | 40K | Well drained | B | Very limited | Very limited |
| Mitten-Tevis complex, 30 to 60 percent slopes | 35K | Somewhat excessively drained | B | Very limited | Very limited |
| Tevis gravelly loam, 30 to 60 percent slopes | 30K | Somewhat excessively drained | B | Very limited | Very limited |
| Waldbillig-Holloway gravelly ashy silt loams, 8 to 30 percent slopes | 28K | Well drained | B | Very limited | Very limited |
| Felan gravelly ashy silt loam, 30 to 60 percent slopes | 27K | Well drained | B | Very limited | Very limited |
| Repp very gravelly loam, cool, 30 to 60 percent slopes | 24K | Well drained | B | Very limited | Very limited |
| Holloway-Rock outcrop complex, 50 to 80 percent slopes | 21K | Somewhat excessively drained | B | Very limited | Very limited |
| Jimlake gravelly silt loam, 4 to 30 percent slopes | 21K | Well drained | B | Very limited | Very limited |
| Bignell gravelly loam, 8 to 30 percent slopes | 20K | Well drained | C | Very limited | Very limited |
| Bigarm gravelly loam, 30 to 60 percent slopes | 20K | Somewhat excessively drained | B | Very limited | Very limited |
| Repp very gravelly loam, 30 to 60 percent slopes | 20K | Well drained | B | Very limited | Very limited |
| Hollandlake-Bata complex, 4 to 30 percent slopes | 20K | Well drained | C | Very limited | Very limited |
| Winkler gravelly loam, cool, 8 to 30 percent slopes | 18K | Somewhat excessively drained | A | Very limited | Very limited |
| Petty gravelly loam, 30 to 60 percent slopes | 17K | Somewhat excessively drained | B | Very limited | Very limited |
| Rock outcrop-Rubble land complex | 17K | D | Not rated | Not rated | |
| Waldbillig-Holloway gravelly ashy silt loams, cool, 8 to 30 percent slopes | 15K | Well drained | B | Very limited | Very limited |
What This Means
Building & Foundations
About 97% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, sandy or gravelly soils with low bearing capacity. A geotechnical assessment is recommended before building.
Septic Systems
About 97% of soils are rated "very limited" for septic absorption fields. The well-drained soils may actually drain too fast for standard leach fields, allowing effluent to reach groundwater. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Soils tend to drain very quickly, meaning nutrients and water don't stick around long. Raised beds with amended soil, drip irrigation, and heavy mulching will give the best results. Compost is your best friend here — it improves water retention dramatically.