What EPA's radon map says about Lincoln County

Lincoln County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Lincoln County sits at the 83rd percentile nationally for radon potential — above 83 of every 100 rated counties.

How Lincoln County compares

About 22,184 people live in Lincoln County, Montana, spread over 3,612.559 square miles. Population density there runs about 6 people per square mile. Among counties sharing Lincoln County's EPA zone, it outranks 50% of them by population. Geologically, Lincoln County is grouped into EPA Region 8 alongside 290 other counties that share its rock and soil setting.

What this actually means for a house in Lincoln County

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Lincoln County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Lincoln County specifically.

If Lincoln County tests above the action level

Mitigation cost doesn't depend on Lincoln County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Montana's state radon program

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

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.