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Radon Levels in Campbell County, Wyoming

EPA puts Campbell County in Zone 1, its highest radon zone, and high results are common there: 43.9% of the 271 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

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  • Share at 4+ pCi/L

    43.9%

    0.4 pts below WY

    Campbell
    43.9%
    Wyoming
    44.3%

    271 tests, 2008 to 2017

  • Median result

    3.5pCi/L

    Below action level

    Campbell
    3.5 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    271

    9th of 22 by tests

    Campbell
    271
    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

    12 of 22

    Middle half

    Campbell
    43.9%
    Sheridan
    69.5%

    By share, of 22 with 30+ tests

Read a result for Campbell County

Starts at Campbell County's median, 3.5 pCi/L

3.5pCi/L

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

EPA’s reading of 3.5 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. Campbell County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Campbell County, At a glance

Campbell County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Campbell 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 98% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Campbell County, 2008 to 2017, laboratory
Under 2 pCi/L: 26%2 to 4 pCi/L: 30%4 pCi/L and above: 44%

Of 271 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Campbell County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L7025.8%
2 to 4 pCi/L8230.3%
4 pCi/L and above11943.9%
What these figures count

These are the 271 tests reported to CDC for Campbell 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

Campbell County, Compared

Campbell County radon figures, compared

Calculated by Radon411

In Campbell County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (119 of 271) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 8.2 points higher. Across 23 Wyoming counties pooled together, 44.3% of tests reached that level, so Campbell County runs 0.4 points below its state.

Of 5 neighbours with a figure, 4 reported a larger share at or above 4 pCi/L and 1 a smaller one; the spread is 34.8% (Johnson County) to 69.5% (Sheridan County). By share, Campbell County is 12th of 22 Wyoming counties with 30 or more tests for the same period.

Half the tests came in under 3.5 pCi/L and half over it; the single highest reached 27.7 pCi/L. Below the action level, 70 tests (25.8%) came in under 2 pCi/L, against 25.5% statewide, and 82 tests (30.3%) fell between 2 and 4, against 30.2% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 43.9% share point the same way here. USGS geology rates 98% of the county's land high radon potential. CDC also counts 14 tests taken after mitigation in Campbell County for the same period: tests in homes where a fix was already in.

CDC's ten-year totals for Campbell County went from 234 tests (2005 to 2014) to 271 (2008 to 2017), the share going from 44.0% to 43.9%.

Campbell County against Wyoming, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Campbell County
Campbell County27143.9%3.5 pCi/LThis county
Wyoming, pooled23 counties, pooled7,63844.3%Not pooled+0.4 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−8.2 points
Lincoln Countyhighest in the state14268.3%7.8 pCi/L+24.4 points
Uinta Countylowest in the state19924.6%2.2 pCi/L−19.3 points
Sheridan County, WYborders it84669.5%5.8 pCi/L+25.6 points
Weston County, WYborders it3265.6%6.3 pCi/L+21.7 points
Powder River County, MTborders it862.5%4.5 pCi/L+18.6 points
Converse County, WYborders it13062.3%4.8 pCi/L+18.4 points
Crook County, WYborders it5158.8%5.1 pCi/L+14.9 points
Johnson County, WYborders it13534.8%3.1 pCi/L−9.1 points
Where Campbell County's reported results fell, 2008 to 2017, laboratory, beside Wyoming and the United States
ResultCampbell County testsCampbell County shareWyoming shareU.S. shareAgainst Wyoming
Under 2 pCi/L7025.8%25.5%39.6%+0.3 points
2 to 4 pCi/L8230.3%30.2%24.7%+0.1 points
4 pCi/L and above11943.9%44.3%35.7%−0.4 points
Campbell 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
Natrona County7 of 221,05455.7%4.3 pCi/L
Fremont County8 of 2261855.7%4.7 pCi/L
Sublette County9 of 226050.0%4.0 pCi/L
Sweetwater County10 of 2240949.6%3.9 pCi/L
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
Campbell County ten-year laboratory totals, against Wyoming's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestWyoming, pooledChange from the row before
2008 to 201727143.9%3.5 pCi/L27.7 pCi/L44.3%+3.0 points
2007 to 201623740.9%3.4 pCi/L27.7 pCi/L44.6%−2.9 points
2006 to 201524243.8%3.6 pCi/L29.1 pCi/L45.3%−0.2 points
2005 to 201423444.0%3.7 pCi/L29.1 pCi/L45.5%First on file

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

Campbell County, Geology

The ground under Campbell County

Predicted

Most of the ground under Campbell County is one class on USGS's geologic map: 97.6% of its land is high radon potential, with 2.4% moderate. 97.6% of it lies in the area the map calls Powder River Basin, to which USGS gives a radon index of 12, in the high band (12 to 17).

USGS's geologic areas under Campbell County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Powder River BasinCretaceous and Tertiary uranium-bearing marginal-marine and fluvial sandstones.High1297.6%
East Powder River BasinUpper Cretaceous marine sedimentary rocks.Moderate112.4%

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

Campbell County beside the ground around it

Campbell County has more high-potential ground than Wyoming as a whole: 97.6% of its land against 72.4%. Of the 6 counties that border it, 1 has more high-potential ground, Sheridan County the most at 98.1%.

Share of land by USGS radon potential: Campbell County, the 6 counties bordering it and Wyoming
AreaEPA zoneLow potentialModerate potentialHigh potential
Campbell CountyZone 1None2.4%97.6%
Crook CountyZone 1None54.7%45.4%
Johnson CountyZone 1None14.4%85.6%
Weston CountyZone 2None54.9%45.1%
Sheridan CountyZone 1None1.9%98.1%
Powder River County, MTZone 1None16.4%83.6%
Converse CountyZone 1None12.5%87.5%
Wyoming23 counties, pooled by land areaVariesNone27.6%72.4%

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

Local help

Campbell County, Local resources

Radon testing and mitigation in Campbell County

What it means

Campbell County, Questions

Questions about radon in Campbell County

Are radon levels high in Campbell County?

Over the 2008 to 2017 laboratory totals, 43.9% of the radon tests reported to CDC for Campbell County, Wyoming were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.5 pCi/L. Of 22 Wyoming counties with 30 or more tests for the same period, 11 reported a higher share; pooled, the state comes to 44.3%.

Which counties border Campbell County?

Campbell County borders 6 counties: Crook County, WY, Johnson County, WY, Weston County, WY, Sheridan County, WY, Powder River County, MT and Converse County, WY.

Products

Campbell County, Products

Testing a home in Campbell County

In Campbell County, 43.9% of 271 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 Campbell 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

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

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Campbell County, Bordering counties

Counties bordering Campbell County

Calculated by Radon411

Campbell County, Cities and towns

Cities and towns in Campbell County

The Census Bureau estimates 48,145 residents in Campbell County for July 1, 2025, 999 more than in 2020 (+2.1%). That works out to 10 people per square mile of land. Gillette alone is home to 34,024 of them, 70.7% of the total. Together its 2 incorporated places hold 74.1% of those residents; the other 25.9% live outside any of them. Reported testing is thin here: 271 tests over 2008 to 2017, or 5.6 for every 1,000 residents (2025 estimate), where Wyoming as a whole comes to 13.0.

From Gillette to Wright, CDC publishes no figure by town: each reads Campbell County's.

The cities and towns in Campbell County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Gillette34,024+1.6%70.7%
Wright1,659+0.7%3.4%

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).

Campbell County, Homes

Homes in Campbell County

Of Campbell County's 19,952 homes, 58% are detached houses, against 68% across Wyoming; 18% are mobile homes. Much of Campbell County is recent building: 36% of its homes have gone up since 2000 and the middle year built is 1989, against 1980 for Wyoming. Owners live in 78% of the occupied homes (Wyoming: 72%), so for most households a test and a fix are their own to order.

Homes in Campbell County, Wyoming, 2019 to 2023
HomesCampbell CountyWyoming
Housing units19,952275,131
Detached houses58%68%
In buildings of 5 or more11%9%
Mobile homes18%12%
Built before 19605%24%
Built since 200036%24%
Middle year built19891980
Owner-occupied78%72%

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