Yellowstone County, MT Shrink-Swell Risk

Yellowstone County, MT's soil, for shrink-swell risk

Moderate

Yellowstone County, MT: USDA's soil survey rates 45.9% of the county "Moderate" for shrink-swell potential (3.94% linear extensibility). A real but modest amount of movement - standard foundations usually hold up, but drainage and moisture control around the foundation still matter more than on low-risk soil.

What Yellowstone County's reading doesn't cover

Two lots a mile apart in Yellowstone County can carry different soil, even though they share one countywide reading. A site-specific soil report, usually $1,000-$5,000, is what an engineer would actually pull before designing a foundation on a lot in Yellowstone County.

What it costs to find out, versus to ignore it

With Yellowstone County, MT rating "Moderate", a geotechnical report is still worthwhile before a build, just less urgent than in a high-risk county. A geotechnical report runs $1,000-$5,000, typically around $2,700. Foundation repair, if a specific lot turns out to differ from the county average, runs $5,000-$15,000.

Where this sits nationally

Nationally, Yellowstone County, MT is the 601-most-constrained of 3,085 rated counties for shrink-swell soil. Within Montana alone it ranks 20 of 54. Yellowstone County covers 2,633 square miles and counts 171,583 residents.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Stonewall County, TX and Lavaca County, TX are worth a look for comparison.

How this reading is built, and its real limits · Moisture management: the cheap fix that works on any soil

More of Montana

Every county in Montana is on this site, including Beaverhead County, MT and Powell County, MT. The full underlying dataset is downloadable directly, one row per county.