Carter County, MT Shrink-Swell Risk

What Carter County, MT's soil means for a foundation

Moderate

USDA's SSURGO data puts Carter County, MT's soil at "Moderate" shrink-swell potential, an area-weighted linear extensibility of 5.16% across 35% of the county's surveyed land. Conventional foundations are the reasonable expectation here, with routine moisture-control practice rather than special engineering.

This is a county figure, not a lot figure

USDA's survey covers the whole of Carter County, MT at once, not any single address. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in Carter County will actually do.

Report cost vs. repair cost

With Carter 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.

How Carter County, MT compares

Nationally, Carter County, MT is the 265-most-constrained of 3,085 rated counties for shrink-swell soil. Within Montana alone it ranks 3 of 54. Carter County covers 3,340 square miles and counts 1,399 residents.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Gem County, ID and Benton County, TN 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 Silver Bow County, MT and Fallon County, MT. The full underlying dataset is downloadable directly, one row per county.