43%tests ≥ 4 pCi/L
3,243tests on record
3.3median pCi/L
Zone 1EPA zone (1993 prediction)

What the data shows

Where Garfield 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 Garfield County compares

Garfield County ranks 5 of 6 among its neighboursShare of tests at or above 4 pCi/L · Colorado county radon test results, 2005–2025 · whisker: 95% range
Routt County52%Rio Blanco County51%Pitkin County46%Eagle County45%Garfield County43%Mesa County33%Colorado 46%
Data table
AreaTests ≥ 4 pCi/LTests
Routt County52%2,753
Rio Blanco County51%193
Pitkin County46%2,767
Eagle County45%3,845
Garfield County43%3,243
Mesa County33%4,318
Colorado (64 counties)46%237,408

Same source as Garfield County. Other bordering counties: Grand County, Utah, Uintah County, Utah.

What it means for your home

About 1 in 2 results in Garfield 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: 3,243. 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