Is Teton County, WY a radon risk area?

EPA places Teton County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. That puts Teton County in the 83rd percentile nationally for radon potential — higher than 83% of the counties EPA has rated.

How Teton County compares

About 23,272 people live in Teton County, Wyoming, spread over 3,996.846 square miles. Averaged across its land area, Teton County runs about 6 people per square mile. Rank 534 by population within its EPA zone puts Teton County at the 50th percentile among zone peers. Teton 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

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Teton County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. That doesn't mean every Teton County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

If Teton County tests above the action level

Nothing about Teton 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

Teton County's test kit answers today; a Airthings radon monitor keeps answering for Teton 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

Teton County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.