Custer County, MT Shrink-Swell Risk

Shrink-swell potential in Custer County, MT

Moderate

Soil across 56.5% of Custer County, MT comes back "Moderate" in USDA's shrink-swell data, averaging 3.36% linear extensibility. That's a middle reading: not the sharp swings that crack a foundation outright, but enough that grading and drainage are worth getting right.

What this number does and doesn't tell you

This is a countywide, area-weighted figure across every soil survey map unit in Custer County, MT - never a reading for one specific parcel. The real answer for one lot is still a site-specific geotechnical report, running about $1,000-$5,000 (typically near $2,700).

Custer County: the real numbers

Custer County's soil reading points toward standard foundation practice as the likely outcome, not the exception. 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

Among the 3,085 rated counties on this site, Custer County, MT ranks 941 most-constrained nationally, and 28 of 54 within Montana. Custer County covers 3,783 square miles and counts 11,964 residents.

See how another county compares

Orleans Parish, LA carries this site's most-constrained reading. Bonner County, ID and Cerro Gordo County, IA 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

Elsewhere in Montana

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