The raw data — ShrinkSwellCheck
USDA SSURGO shrink-swell data for 3,144 US counties
Every county page on ShrinkSwellCheck is generated from this same table: FIPS code, county and state, land area, population, the area-weighted linear extensibility reading, the dominant shrink-swell class, and that class's share of the county's surveyed land. Sourced directly from USDA's Soil Data Access - see the data-quality guide for exactly how it's built.