Is Park County, CO a radon risk area?

EPA places Park 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. Nationally, Park County ranks higher in radon potential than 81% of rated counties (the 81st percentile).

How Park County compares

About 18,316 people live in Park County, Colorado, spread over 2,193.51 square miles. Population density there runs about 8 people per square mile. Rank 595 by population within its EPA zone puts Park County at the 44th percentile among zone peers. Geologically, Park County is grouped into EPA Region 8 alongside 290 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Park County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. Some Park County homes will test comfortably under the action level despite the county's Zone 1 rating — the only way to know which kind of home you have is an actual test.

If Park County tests above the action level

Nothing about Park 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 Colorado's state radon program

Park County's test kit answers today; a Airthings radon monitor keeps answering for Park 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 Park County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.