Expansive Soil in North Dakota: County Ratings
1 of the 53 rated counties in North Dakota have a dominant shrink-swell rating of High or Very High. Each rating below is the NRCS shrink-swell class covering the largest share of the county's mapped soil acres, computed from USDA SSURGO data. Open a county for the full class breakdown and what it means for a slab foundation.
| County | Dominant class | High + Very High share | Survey coverage |
|---|---|---|---|
| Adams County | Low | 35% | 100% |
| Barnes County | Moderate | 7% | 99% |
| Benson County | Low | 11% | 98% |
| Billings County | Low | 26% | 99% |
| Bottineau County | Moderate | 16% | 99% |
| Bowman County | Low | 30% | 99% |
| Burke County | Moderate | 28% | 99% |
| Burleigh County | Moderate | 12% | 97% |
| Cass County | Very High | 42% | 99% |
| Cavalier County | Moderate | 18% | 100% |
| Dickey County | Moderate | 11% | 99% |
| Divide County | Moderate | 21% | 100% |
| Dunn County | Low | 22% | 96% |
| Eddy County | Low | 4% | 98% |
| Emmons County | Moderate | 13% | 96% |
| Foster County | Low | 4% | 99% |
| Golden Valley County | Low | 6% | 100% |
| Grand Forks County | Moderate | 7% | 99% |
| Grant County | Low | 23% | 99% |
| Griggs County | Low | 8% | 99% |
| Hettinger County | Low | 44% | 100% |
| Kidder County | Moderate | 7% | 93% |
| LaMoure County | Moderate | 10% | 99% |
| Logan County | Moderate | 11% | 96% |
| McHenry County | Low | 7% | 98% |
| McIntosh County | Moderate | 9% | 95% |
| McKenzie County | Low | 18% | 97% |
| McLean County | Moderate | 9% | 90% |
| Mercer County | Moderate | 16% | 93% |
| Morton County | Low | 33% | 99% |
| Mountrail County | Moderate | 11% | 95% |
| Nelson County | Moderate | 11% | 98% |
| Oliver County | Moderate | 11% | 99% |
| Pembina County | Low | 30% | 99% |
| Pierce County | Low | 6% | 96% |
| Ramsey County | Moderate | 24% | 93% |
| Ransom County | Moderate | 5% | 99% |
| Renville County | Moderate | 2% | 98% |
| Richland County | Low | 34% | 99% |
| Rolette County | Low | 20% | 96% |
| Sargent County | Moderate | 10% | 99% |
| Sheridan County | Moderate | 12% | 97% |
| Sioux County | Low | 36% | 96% |
| Slope County | Low | 23% | 99% |
| Stark County | Low | 34% | 100% |
| Steele County | Moderate | 3% | 100% |
| Stutsman County | Moderate | 10% | 96% |
| Towner County | Low | 15% | 100% |
| Traill County | Low | 35% | 100% |
| Walsh County | Moderate | 20% | 99% |
| Ward County | Moderate | 7% | 99% |
| Wells County | Low | 6% | 98% |
| Williams County | Moderate | 6% | 97% |
How these ratings are computed
Ratings come from USDA NRCS SSURGO soil survey data: for each soil component we take the maximum linear extensibility percent (lep_r) in the top 100 cm, apply the NRCS Handbook Part 618 class limits (Low under 3 percent, Moderate 3 to 6, High 6 to 9, Very High 9 and above), assign map units by plurality of component percent, and roll acres up to the county. Full details on the methodology section of the lookup page. A county rating is not a parcel-level geotechnical assessment.