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Radon Levels in Rio Blanco County, Colorado

EPA puts Rio Blanco County in Zone 1, its highest radon zone, and only 15 radon tests from it are on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    66.3%

    22.1 pts above CO

    Rio Blanco
    66.3%
    Colorado
    44.2%

    92 tests, 2018

  • Median result

    5.0pCi/L

    Action level reached

    Rio Blanco
    5.0 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2018

  • Tests reported

    92

    33rd of 40 by tests

    Rio Blanco
    92
    Jefferson
    5,268

    Reported to CDC before any fix, 2018

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in Colorado

    3 of 40

    Top quarter

    Rio Blanco
    66.3%
    Morgan
    78.9%

    By share, of 40 with 30+ tests

Read a result for Rio Blanco County

Starts at Rio Blanco County's median, 5.0 pCi/L

5.0pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 5.0 pCi/L

At or above 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Rio Blanco County's median reported result, 2018.

Interpret this readingWhat a fix costs

The data

Rio Blanco County, At a glance

Rio Blanco County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Rio Blanco County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

USGS geologic potential: High across 68% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Rio Blanco County, 2023

Share of reported tests at or above 4 pCi/L, by year, Rio Blanco County
Share of reported tests at or above 4 pCi/L, by year, Rio Blanco County
YearShare of reported tests at or above 4 pCi/L
201466.7%
201572.2%
201658.3%
201766.7%
201866.3%
201943.5%
202054.3%
202156.3%
202235.7%
202320.0%

2023: 20.0%. Across these years the share ran from 20.0% to 72.2%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 15 tests were reported to CDC for Rio Blanco County over 2023, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.

Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

How to read these figures

Rio Blanco County, Compared

Rio Blanco County radon figures, compared

Calculated by Radon411

More than half: 66.3% of the 92 radon tests reported to CDC for Rio Blanco County in 2018 read at least 4 pCi/L. That places it 3rd of 40 Colorado counties with 30 or more tests for the same period. That is 22.1 points above the 44.2% pooled from 59 Colorado counties.

The newest figure, in 2023, counts only 15 tests (20.0% at or above 4 pCi/L), too few to compare, so this reading uses the 92-test figure.

The median result, 5.0 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 143.6 pCi/L. The rest split 12.0% under 2 pCi/L and 21.7% from 2 to 4 (Colorado: 34.9% and 20.9%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 66.3% share point the same way here.

No bordering county with a figure for the same period reported a higher share; the closest is Routt County at 47.1%, the lowest Garfield County at 38.9%. Statewide for the same period, Morgan County reported the highest share (78.9%) and Las Animas County the lowest (13.7%).

The busiest year on file was 2018, with 92 tests reported; the quietest, 2014, had 3.

Nationally, every county with a figure for the same period pools to 29.1%; Rio Blanco County sits 37.2 points above it.

Rio Blanco County against Colorado, the United States and nearby counties, 2018
AreaTestsAt or above 4 pCi/LMedianDifference from Rio Blanco County
Rio Blanco County9266.3%5.0 pCi/LThis county
Colorado, pooled59 counties, pooled33,02544.2%Not pooled−22.1 points
United States, pooled773 counties, pooled389,55129.1%Not pooled−37.2 points
Morgan Countyhighest in the state3878.9%5.4 pCi/L+12.6 points
Las Animas Countylowest in the state11713.7%0.7 pCi/L−52.6 points
Routt County, COborders it22147.1%3.9 pCi/L−19.2 points
Uintah County, UTborders it4346.5%3.7 pCi/L−19.8 points
Garfield County, COborders it38838.9%3.1 pCi/L−27.4 points
Moffat County, COborders it2326.1%2.6 pCi/L−40.2 points
Where Rio Blanco County's reported results fell, 2018, beside Colorado and the United States
ResultRio Blanco County testsRio Blanco County shareColorado shareU.S. shareAgainst Colorado
Under 2 pCi/L1112.0%34.9%48.3%−22.9 points
2 to 4 pCi/L2021.7%20.9%22.6%+0.8 points
4 pCi/L and above6166.3%44.2%29.1%+22.1 points
Rio Blanco County ranked among the 40 Colorado counties with 30 or more tests, by share at or above 4 pCi/L, 2018
CountyRankTestsAt or above 4 pCi/LMedian
Morgan County1 of 403878.9%5.4 pCi/L
Ouray County2 of 4010069.0%8.4 pCi/L
Rio Blanco County3 of 409266.3%5.0 pCi/L
Chaffee County4 of 4015164.9%5.5 pCi/L
Teller County5 of 4027761.4%6.2 pCi/L
Gilpin County6 of 405658.9%6.4 pCi/L
Lake County7 of 4010257.8%4.5 pCi/L
Montrose County8 of 4036556.4%4.6 pCi/L
Pueblo County9 of 4035054.6%4.6 pCi/L
Fremont County10 of 4010451.9%4.0 pCi/L
Larimer County11 of 402,25151.1%4.1 pCi/L
Rio Blanco County radon tests by year, against Colorado's pooled share
YearTestsAt or above 4 pCi/LMedianHighestColorado, pooledChange from the row before
20231520.0%1.9 pCi/L19.2 pCi/L38.9%−15.7 points
20221435.7%2.8 pCi/L6.3 pCi/L38.6%−20.6 points
20211656.3%4.3 pCi/L42.2 pCi/L47.3%+2.0 points
20203554.3%4.3 pCi/L13.1 pCi/L41.9%+10.8 points
20192343.5%3.5 pCi/L8.9 pCi/L44.1%−22.8 points
20189266.3%5.0 pCi/L143.6 pCi/L44.2%−0.4 points
20171266.7%4.9 pCi/L12.6 pCi/L41.0%+8.4 points
20161258.3%5.3 pCi/L16.0 pCi/L38.5%−13.9 points
20151872.2%5.2 pCi/L22.6 pCi/L47.2%+5.5 points
2014366.7%5.3 pCi/L9.5 pCi/L46.5%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Rio Blanco County, State data

Colorado's own radon test data

Measured

What Colorado's own agencies publish about radon tests in Rio Blanco County, with their period. These are not CDC's figures and are never added to them.

MeasuredState figures, not CDC's

What Colorado CDPHE reports for Rio Blanco County

Radon data (county results): radon test results received from radon testing labs, primarily short-term household tests taken by the homeowner. Period: 2005-2025.

Share over 4 pCi/L

51.3%

99 of 193 tests

Median result

4.1 pCi/L

Highest result

143.6 pCi/L

Tests behind these figures

193 tests

  • CDPHE says these data do not give actual radon levels in homes that have not been tested.
  • When possible, only tests conducted before a mitigation system was installed are used.
  • Some counties have very small numbers of test results, and their summaries may be less representative.
  • These figures describe tests reported to Colorado CDPHE in this area. They count a different set of tests than CDC's figures and are not a reading of any one home.

Measured: Colorado CDPHE data, 2005-2025.

Rio Blanco County, Geology

The ground under Rio Blanco County

Predicted

USGS's geologic map splits Rio Blanco County: 68.2% of its land is high radon potential and 31.8% moderate. The map puts 68.2% of Rio Blanco County in the area it calls Paradox Basin and 31.8% in Western Slope. USGS gives the first a radon index of 13, in the high band (12 to 17), and the second 11, in the moderate band (9 to 11).

USGS's geologic areas under Rio Blanco County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Paradox BasinTertiary sandstone, siltstone and shale.High1368.2%
Western SlopePaleozoic and Mesozoic sandstone, siltstone, shale, basalt.Moderate1131.8%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Rio Blanco County beside the ground around it

On high-potential ground Rio Blanco County is close to Colorado as a whole: 68.2% of its land against 74.8%. Of the 4 counties that border it, 1 has more high-potential ground, Uintah County, UT the most at 69.5%.

Share of land by USGS radon potential: Rio Blanco County, the 4 counties bordering it and Colorado
AreaEPA zoneLow potentialModerate potentialHigh potential
Rio Blanco CountyZone 1None31.8%68.2%
Garfield CountyZone 1None42.5%57.5%
Moffat CountyZone 1None38.6%61.4%
Routt CountyZone 2None65.3%34.7%
Uintah County, UTZone 1None30.5%69.5%
Colorado64 counties, pooled by land areaVariesNone25.2%74.8%

The map rates the ground, not the air in any home.

Local help

Rio Blanco County, Local resources

Radon testing and mitigation in Rio Blanco County

What Colorado's program says
Licensing of radon professionals
Listed contractors are certified by the National Radon Proficiency Program or the National Radon Safety Board, and must be licensed by the Colorado Department of Regulatory Agencies.
Disclosure when a home is sold or rented
As of August 7, 2023, landlords in Colorado are required to disclose radon information when a tenant signs a lease agreement.

What it means

Rio Blanco County, Questions

Questions about radon in Rio Blanco County

Are radon levels high in Rio Blanco County?

In 2023, 20.0% of the radon tests reported to CDC for Rio Blanco County, Colorado were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.9 pCi/L. Of 40 Colorado counties with 30 or more tests for the same period, 2 reported a higher share; pooled, the state comes to 44.2%.

Which counties border Rio Blanco County?

Rio Blanco County borders 4 counties: Garfield County, CO, Moffat County, CO, Routt County, CO and Uintah County, UT.

Products

Rio Blanco County, Products

Testing a home in Rio Blanco County

In Rio Blanco County, 66.3% of 92 tests reported to CDC in 2018 reached 4 pCi/L, against 44.2% pooled across Colorado. In Zone 1 the year-round level in Rio Blanco County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.

Test kits and monitors3

See every kit and monitor

Rio Blanco County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Rio Blanco County

Explore

Rio Blanco County, Bordering counties

Counties bordering Rio Blanco County

Calculated by Radon411

Rio Blanco County, Cities and towns

Cities and towns in Rio Blanco County

The Census Bureau estimates 6,683 residents in Rio Blanco County for July 1, 2025, 161 more than in 2020 (+2.5%). Spread over its land, that is 2.1 people to the square mile. Its largest town, Meeker, has 2,417 residents, 36.2% of the total. Together its 2 incorporated places hold 70.6% of those residents; the other 29.4% live outside any of them. Testing is reported here more often than across the state: CDC's 92 reported tests for 2018 come to 13.8 for every 1,000 residents (2025 estimate), against 5.5 for Colorado.

From Meeker to Rangely, CDC publishes no figure by town: each reads Rio Blanco County's.

The cities and towns in Rio Blanco County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Meeker2,417+1.7%36.2%
Rangely2,304+0.2%34.5%

2 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).

Rio Blanco County, Homes

Homes in Rio Blanco County

Rio Blanco County is a place of houses on their own lots: 78% of its 3,288 homes are detached single-family houses, against 62% across Colorado. Half of its homes were built before 1980, close to Colorado's 1987: 19% date from before 1960 and 21% from 2000 or later. Owners live in 76% of the occupied homes (Colorado: 66%), so for most households a test and a fix are their own to order.

Homes in Rio Blanco County, Colorado, 2019 to 2023
HomesRio Blanco CountyColorado
Housing units3,2882,545,124
Detached houses78%62%
In buildings of 5 or more7%22%
Mobile homes8%4%
Built before 196019%16%
Built since 200021%31%
Middle year built19801987
Owner-occupied76%66%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.