Is Musselshell County, MT a radon risk area?

Musselshell County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. That puts Musselshell County in the 36th percentile nationally for radon potential — higher than 36% of the counties EPA has rated.

How Musselshell County compares

About 5,452 people live in Musselshell County, Montana, spread over 1,868.958 square miles. That works out to roughly 3 people per square mile. Rank 932 by population within its EPA zone puts Musselshell County at the 10th percentile among zone peers. EPA's geology-based Region 8 groups Musselshell County with 290 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Neither at the 4 pCi/L action level nor down at the roughly 1.3 pCi/L national indoor norm, Musselshell County's Zone 2 prediction lands in the gap between the two. A Zone 2 rating is a moderate county-wide average, not a guarantee about any one house in Musselshell County — testing is the only way to know an individual home's actual level.

Next steps for a home in Musselshell County

Nothing about Musselshell 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 Montana's state radon program

Musselshell County's test kit answers today; a Airthings radon monitor keeps answering for Musselshell County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

More on how this number was built

Musselshell County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Musselshell County carries, the zone explainer covers what it does and doesn't tell you about any one house.