Septic soil in Hot Springs County, WY, by the numbers
Very limited
In Hot Springs County, WY, 46.6% of the surveyed land carries a "Very limited" rating for a standard septic drain field. Practically, that rules out a simple gravity system for most of the county - 46.6% of it sits in USDA's most-constrained bucket. Hot Springs County, WY is 2,004.431 square miles with a population of 4,625.
What Hot Springs County's reading doesn't cover
USDA's survey covers the whole of Hot Springs County, WY at once, not any single address. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Hot Springs County will actually do.
What a system would cost here
With 46.6% of Hot Springs County rating "Very limited", a standard gravity system is not a safe assumption here. The engineered-system range, $10,000-$40,000 (mound or aerobic treatment), is the more realistic number to plan around, against $3,000-$8,000 for a conventional system on the rare lot that passes.
How Hot Springs County, WY compares
Nationally, Hot Springs County, WY is the 2,903-most-constrained of 3,058 rated counties for septic soil. Within Wyoming alone it ranks 21 of 22.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems