26 counties mapped. On average, 23% of Montana county soil area is high shrink-swell clay (USDA SSURGO).
Foundation problems get more expensive the longer they wait. Get an assessment and repair quotes from independent local pros.
Get repair quotes →| County | Tier | High-risk % | Moderate % |
|---|---|---|---|
| Petroleum | Severe | 57% | 18% |
| Fergus | Severe | 55% | 18% |
| Valley | Severe | 51% | 38% |
| Carter | Severe | 49% | 26% |
| Treasure | Severe | 43% | 22% |
| Liberty | Severe | 34% | 57% |
| Yellowstone | Severe | 33% | 27% |
| Toole | High | 29% | 62% |
| Hill | High | 29% | 60% |
| Musselshell | High | 25% | 39% |
| Glacier County Area and Part of Pondera | High | 23% | 48% |
| Rosebud County Area and Part of Big Horn | High | 22% | 35% |
| Fallon | High | 21% | 31% |
| Garfield | High | 20% | 26% |
| Wibaux | High | 20% | 37% |
| Red Rock Lakes Area - Part of Beaverhead | Moderate | 14% | 29% |
| Horse Prairie-South Valley Area - Part of Beaverhead | Moderate | 12% | 38% |
| McCone | Moderate | 12% | 56% |
| Big Hole Area - Part of Beaverhead | Moderate | 10% | 56% |
| Prairie | Moderate | 9% | 25% |
| Dawson | Moderate | 8% | 41% |
| Richland | Moderate | 7% | 58% |
| Sheridan | Moderate | 6% | 67% |
| Jefferson County Area and Part of Silver Bow | Low | 2% | 30% |
| Flathead County Area and Part of Lincoln | Low | 2% | 17% |
| Dillon Area - Part of Beaverhead | Low | 0% | 35% |
Risk metrics are computed from USDA SSURGO soil survey data (linear extensibility of soil components, area-weighted by county). Soil varies lot to lot — this is county-scale context, not a substitute for a site-specific geotechnical or structural assessment.