Is Platte County, WY a radon risk area?

Platte County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. That puts Platte County in the 39th percentile nationally for radon potential — higher than 39% of the counties EPA has rated.

Where Platte County sits nationally

About 8,512 people live in Platte County, Wyoming, spread over 2,081.459 square miles. That works out to roughly 4 people per square mile. Rank 854 by population within its EPA zone puts Platte County at the 17th percentile among zone peers. Platte County falls in EPA Radon Region 8, one of 291 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Platte County's Zone 2 prediction clears the 1.3 pCi/L national indoor average without reaching EPA's own 4 pCi/L point for recommending a fix. Middle-of-the-pack doesn't mean risk-free for any one Platte County address — a moderate county average still leaves individual homes to test either side of it.

Next steps for a home in Platte County

Nothing about Platte County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find Wyoming's state radon program

Platte County's test kit answers today; a Airthings radon monitor keeps answering for Platte County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Platte County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.