27%tests ≥ 4 pCi/L
784tests on record
2.4median pCi/L
Zone 1EPA zone (1993 prediction)

What the data shows

Where Montezuma County sits among Colorado's 64 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Colorado county radon test results, 2005–2025
0%20%40%60%

How Montezuma County compares

Montezuma County has the lowest share of high results among its neighboursShare of tests at or above 4 pCi/L · Colorado county radon test results, 2005–2025 · whisker: 95% range
San Juan County64%Dolores County46%La Plata County43%Montezuma County27%Colorado 46%
Data table
AreaTests ≥ 4 pCi/LTests
San Juan County64%108
Dolores County46%39
La Plata County43%3,365
Montezuma County27%784
Colorado (64 counties)46%237,408

Same source as Montezuma County. Other bordering counties: Apache County, Arizona, San Juan County, New Mexico, San Juan County, Utah.

What it means for your home

About 1 in 4 results in Montezuma County were at or above 4 pCi/L, where the EPA recommends a fix. Only a test shows your own home's level.

Levels in pCi/L from the EPA. The WHO reference level is 100 Bq/m³, about 2.7 pCi/L.

Test your home

Start with a short-term test (2–90 days) and confirm a result of 4 pCi/L or more with a second test. EPA guide

Sponsored: we earn a commission on purchases through these links. We haven't tested Airthings monitors yet.

Prefer a digital monitor? See Airthings radon monitors, or enter code radonbycounty-10OFF at their discount store for 10% off.

Fixing high radon

No local job records yet. National range: $800–$2,500, average $1,200 (EPA, 2003). Cost guide →

Colorado licenses radon mitigators. Source

Buying or selling here

Since August 2023, Colorado home sale contracts must include the seller's known radon test, report and mitigation history and the state health department's radon brochure (SB23-206). Source

Checked against the official text on 2026-11-03. Not legal advice.

About this data

Source: Colorado county radon test results (Colorado Department of Public Health and Environment). Period: 2005–2025. Tests: 784. Read the methodology →

These are voluntary and real-estate tests, not a random sample of homes, so they describe tested homes rather than every home.

About this page

Published by Ray Roman, editor of Radon by County. Figures are loaded from the cited source and spot-checked against it. Editorial policy · About us