Valley County, MT Shrink-Swell Risk

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

Moderate

Valley County, MT: USDA's soil survey rates 40.4% of the county "Moderate" for shrink-swell potential (3.98% 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 Valley County's reading doesn't cover

Two lots a mile apart in Valley 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 Valley County.

What it costs to find out, versus to ignore it

With Valley 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, Valley County, MT is the 581-most-constrained of 3,085 rated counties for shrink-swell soil. Within Montana alone it ranks 18 of 54. Valley County, MT is 4,926 square miles with a population of 7,434.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Butler County, KY and Barton County, KS 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 Madison County, MT and Pondera County, MT. The full underlying dataset is downloadable directly, one row per county.