Montrose County, CO radon potential
Montrose County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Montrose County sits at the 89th percentile nationally for radon potential — above 89 of every 100 rated counties.
Where Montrose County sits nationally
Montrose County, Colorado is home to about 44,806 people across 2,240.946 square miles. Population density there runs about 20 people per square mile. Within its own EPA zone, Montrose County is bigger by population than 67% of the counties that share it. Geologically, Montrose 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 Montrose County
Where the national indoor average runs about 1.3 pCi/L, Montrose County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. Being in Zone 1 raises the odds Montrose County homes test above the action level, but it does not mean any specific house does — EPA recommends every home be tested, in every zone, because the only way to know is to test.
If Montrose 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 Colorado's state radon program
For Montrose County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Montrose County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.
Where Montrose County's figures come from
Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.