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Radon Levels in Carbon County, Wyoming

EPA puts Carbon County in Zone 1, its highest radon zone, and high results are common there: 41.3% of the 80 radon tests reported to CDC (2008 to 2017, laboratory totals) came back at or above 4 pCi/L. 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

    41.3%

    3.0 pts below WY

    Carbon
    41.3%
    Wyoming
    44.3%

    80 tests, 2008 to 2017

  • Median result

    3.0pCi/L

    Below action level

    Carbon
    3.0 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    80

    18th of 22 by tests

    Carbon
    80
    Laramie
    1,834

    Reported to CDC before any fix, 2008 to 2017

  • 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 Wyoming

    16 of 22

    Middle half

    Carbon
    41.3%
    Sheridan
    69.5%

    By share, of 22 with 30+ tests

Read a result for Carbon County

Starts at Carbon County's median, 3.0 pCi/L

3.0pCi/L

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

EPA’s reading of 3.0 pCi/L

Between 2 and 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 between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Carbon County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Carbon County, At a glance

Carbon County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Carbon 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 71% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Carbon County, 2008 to 2017, laboratory

Reported results by concentration band, Carbon County, 2008 to 2017, laboratory
Under 2 pCi/L: 34%2 to 4 pCi/L: 25%4 pCi/L and above: 41%

Of 80 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Carbon County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L2733.8%
2 to 4 pCi/L2025.0%
4 pCi/L and above3341.3%
What these figures count

These are the 80 tests reported to CDC for Carbon County over 2008 to 2017 (laboratory totals), many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.

Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).

How to read these figures

Carbon County, Compared

Carbon County radon figures, compared

Calculated by Radon411

In Carbon County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (33 of 80) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 5.6 points higher. Across 23 Wyoming counties pooled together, 44.3% of tests reached that level, so Carbon County runs 3.0 points below its state.

Of 7 neighbours with a figure, 6 reported a larger share at or above 4 pCi/L and 1 a smaller one; the spread is 27.9% (Albany County) to 62.3% (Converse County). By share, Carbon County is 16th of 22 Wyoming counties with 30 or more tests for the same period.

Half the tests came in under 3.0 pCi/L and half over it; the single highest reached 47.9 pCi/L. Below the action level, 27 tests (33.8%) came in under 2 pCi/L, against 25.5% statewide, and 20 tests (25.0%) fell between 2 and 4, against 30.2% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 41.3% share point the same way here. USGS geology rates 71% of the county's land high radon potential.

CDC's ten-year totals for Carbon County went from 62 tests (2005 to 2014) to 80 (2008 to 2017), the share going from 32.3% to 41.3%.

Carbon County against Wyoming, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Carbon County
Carbon County8041.3%3.0 pCi/LThis county
Wyoming, pooled23 counties, pooled7,63844.3%Not pooled+3.0 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−5.6 points
Sheridan Countyhighest in the state84669.5%5.8 pCi/L+28.2 points
Uinta Countylowest in the state19924.6%2.2 pCi/L−16.7 points
Jackson County, COborders it580.0%24.8 pCi/L+38.7 points
Converse County, WYborders it13062.3%4.8 pCi/L+21.0 points
Natrona County, WYborders it1,05455.7%4.3 pCi/L+14.4 points
Fremont County, WYborders it61855.7%4.7 pCi/L+14.4 points
Moffat County, COborders it21855.0%4.3 pCi/L+13.7 points
Sweetwater County, WYborders it40949.6%3.9 pCi/L+8.3 points
Routt County, COborders it1,11749.3%3.9 pCi/L+8.0 points
Albany County, WYborders it39427.9%2.7 pCi/L−13.4 points
Where Carbon County's reported results fell, 2008 to 2017, laboratory, beside Wyoming and the United States
ResultCarbon County testsCarbon County shareWyoming shareU.S. shareAgainst Wyoming
Under 2 pCi/L2733.8%25.5%39.6%+8.3 points
2 to 4 pCi/L2025.0%30.2%24.7%−5.2 points
4 pCi/L and above3341.3%44.3%35.7%−3.0 points
Carbon County ranked among the 22 Wyoming counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Teton County11 of 2227844.6%3.4 pCi/L
Campbell County12 of 2227143.9%3.5 pCi/L
Park County13 of 2250542.8%3.4 pCi/L
Big Horn County14 of 229942.4%3.5 pCi/L
Goshen County15 of 2216841.7%3.3 pCi/L
Carbon County16 of 228041.3%3.0 pCi/L
Washakie County17 of 2213038.5%3.2 pCi/L
Johnson County18 of 2213534.8%3.1 pCi/L
Albany County19 of 2239427.9%2.7 pCi/L
Platte County20 of 2213226.5%2.4 pCi/L
Laramie County21 of 221,83425.5%2.5 pCi/L
Carbon County ten-year laboratory totals, against Wyoming's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestWyoming, pooledChange from the row before
2008 to 20178041.3%3.0 pCi/L47.9 pCi/L44.3%−0.7 points
2007 to 20168142.0%3.0 pCi/L47.9 pCi/L44.6%+5.0 points
2006 to 20158137.0%2.7 pCi/L31.6 pCi/L45.3%+4.7 points
2005 to 20146232.3%2.4 pCi/L31.6 pCi/L45.5%First on file

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

Carbon County, Geology

The ground under Carbon County

Predicted

USGS's geologic map splits Carbon County: 70.8% of its land is high radon potential and 29.2% moderate. The map puts 34.3% of Carbon County in the area it calls Wind River Basin and 29.2% in Hanna Basin, with 3 smaller areas beside them. USGS gives the first a radon index of 12, in the high band (12 to 17), and the second 11, in the moderate band (9 to 11).

USGS's geologic areas under Carbon County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Wind River BasinCretaceous and Tertiary uranium-bearing marginal-marine and fluvial sandstones.High1234.3%
Hanna BasinCretaceous marine shale, siltstone, and sandstone.Moderate1129.2%
Laramie MountainsPrecambrian anorthosite, monzonite, gneissic granite, and granite.High1217.7%
Green River BasinCretaceous and Tertiary uranium-bearing marginal-marine and fluvial sandstones.High129.4%
Wind River MountainsPrecambrian granite, glacial till in valleys.High129.3%

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

Carbon County beside the ground around it

On high-potential ground Carbon County is close to Wyoming as a whole: 70.8% of its land against 72.4%. Of the 8 counties that border it, 5 have more high-potential ground, Jackson County, CO the most at 100%.

Share of land by USGS radon potential: Carbon County, the 8 counties bordering it and Wyoming
AreaEPA zoneLow potentialModerate potentialHigh potential
Carbon CountyZone 1None29.2%70.8%
Albany CountyZone 1None0.3%99.7%
Natrona CountyZone 1None39.4%60.6%
Jackson County, COZone 1NoneNone100%
Routt County, COZone 2None65.3%34.7%
Converse CountyZone 1None12.5%87.5%
Moffat County, COZone 1None38.6%61.4%
Sweetwater CountyZone 1None0.4%99.6%
Fremont CountyZone 1None7.3%92.7%
Wyoming23 counties, pooled by land areaVariesNone27.6%72.4%

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

Local help

Carbon County, Local resources

Radon testing and mitigation in Carbon County

What it means

Carbon County, Questions

Questions about radon in Carbon County

Are radon levels high in Carbon County?

Over the 2008 to 2017 laboratory totals, 41.3% of the radon tests reported to CDC for Carbon County, Wyoming were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.0 pCi/L. Of 22 Wyoming counties with 30 or more tests for the same period, 15 reported a higher share; pooled, the state comes to 44.3%.

Which counties border Carbon County?

Carbon County borders 8 counties: Albany County, WY, Natrona County, WY, Jackson County, CO, Routt County, CO, Converse County, WY, Moffat County, CO, Sweetwater County, WY and Fremont County, WY.

Products

Carbon County, Products

Testing a home in Carbon County

In Carbon County, 41.3% of 80 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 44.3% pooled across Wyoming. In Zone 1 the year-round level in Carbon 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

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

Explore

Carbon County, Bordering counties

Counties bordering Carbon County

Calculated by Radon411

Carbon County, Cities and towns

Cities and towns in Carbon County

About 14,013 people live in Carbon County by the Census Bureau's estimate for July 1, 2025, 495 fewer than in 2020 (−3.4%). Spread over its land, that is 1.8 people to the square mile. Rawlins alone is home to 7,745 of them, 55.3% of the total. Together its 10 incorporated places hold 84.8% of those residents; the other 15.2% live outside any of them. Reported testing is thin here: 80 tests over 2008 to 2017, or 5.7 for every 1,000 residents (2025 estimate), where Wyoming as a whole comes to 13.0.

From Rawlins to Riverside, CDC publishes no figure by town: each reads Carbon County's.

The cities and towns in Carbon County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Rawlins7,745−6.1%55.3%
Saratoga1,766+4.4%12.6%
Hanna645−4.2%4.6%
Encampment446−1.3%3.2%
Baggs404−0.2%2.9%
Sinclair358−4.0%2.6%
Medicine Bow235−2.5%1.7%
Elk Mountain146−4.6%1.0%
Dixon74+4.2%0.5%
Riverside66−1.5%0.5%

10 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).

Carbon County, Homes

Homes in Carbon County

Of Carbon County's 8,220 homes, 71% are detached houses, against 68% across Wyoming; 16% are mobile homes. Half of its homes were built before 1973, close to Wyoming's 1980: 36% date from before 1960 and 14% from 2000 or later. Owners live in 77% of the occupied homes (Wyoming: 72%), so for most households a test and a fix are their own to order.

Homes in Carbon County, Wyoming, 2019 to 2023
HomesCarbon CountyWyoming
Housing units8,220275,131
Detached houses71%68%
In buildings of 5 or more6%9%
Mobile homes16%12%
Built before 196036%24%
Built since 200014%24%
Middle year built19731980
Owner-occupied77%72%

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