Chouteau County, MT radon potential
Chouteau County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally, Chouteau County ranks higher in radon potential than 72% of rated counties (the 72nd percentile).
How Chouteau County compares
Chouteau County, Montana is home to about 5,880 people across 3,972.52 square miles. That works out to roughly 1 people per square mile. Within its own EPA zone, Chouteau County is bigger by population than 17% of the counties that share it. Geologically, Chouteau 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
Chouteau County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. That doesn't mean every Chouteau 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.
Next steps for a home in Chouteau County
A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.
Find Montana's state radon program
For Chouteau County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Chouteau County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.
Where Chouteau County's figures come from
Chouteau County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.