Is Caribou County, ID a radon risk area?

EPA's own radon map rates Caribou County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. That puts Caribou County in the 37th percentile nationally for radon potential — higher than 37% of the counties EPA has rated.

How Caribou County compares

About 7,239 people live in Caribou County, Idaho, spread over 1,764.194 square miles. Averaged across its land area, Caribou County runs about 4 people per square mile. Rank 896 by population within its EPA zone puts Caribou County at the 13th percentile among zone peers. EPA's geology-based Region 10 groups Caribou County with 141 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Call it a middle case: above the 1.3 pCi/L most US homes average, below the 4 pCi/L line EPA uses to recommend mitigation — that's Caribou County's Zone 2 prediction. A county-wide moderate average, like Caribou County's, can still hide a specific house well above or below it — testing is what actually answers the question.

Testing and mitigation in Caribou County

Nothing about Caribou 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 Idaho's state radon program

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

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. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.