Prairie County, MT Radon Zone Data

Prairie County, MT radon potential

EPA's own radon map rates Prairie County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. That puts Prairie County in the 66th percentile nationally for radon potential — higher than 66% of the counties EPA has rated.

Prairie County by the numbers

Prairie County, Montana is home to about 1,112 people across 1,736.603 square miles. Population density there runs about 1 people per square mile. Within its own EPA zone, Prairie County is bigger by population than 0% of the counties that share it. Geologically, Prairie 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 Prairie County

Prairie 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. Some Prairie 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 Prairie County tests above the action level

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 Prairie County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Prairie County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

Where Prairie County's figures come from

Prairie 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.