Title reports $49 · others $100–$400See prices

Radon in Park County, Wyoming

Park County, Wyoming, is in EPA radon Zone 1: predicted average indoor radon screening level greater than 4 pCi/L (highest potential). Radon laboratories reported 258 building tests here for 2008 to 2017: median 3.4 pCi/L, with 42.8% at or above EPA's 4 pCi/L action level (Wyoming 43.1%, US 36.5%).

Zone 1
EPA radon zone (1993 county map)
3.4
median lab test, pCi/L (2008-2017)
42.8%
of lab tests at or above 4 pCi/L
258
buildings tested by labs, 2008-2017

Radon test results in Park County

Radon test results on file for Park County, WY, with state and national comparison
Test resultsPeriodTestsTypical result4 pCi/L or more
Radon testing laboratories2008-2017258median 3.4 pCi/L42.8%
Wyoming, all counties (labs)2008-20174,713n/a43.1%
United States (labs)2008-20171,408,802n/a36.5%

Test results describe buildings whose owners chose to test and whose results reached the lab or agency, not a random sample; small counts swing widely. State and US shares are computed from county counts and percents. The laboratory data comes from national radon testing laboratories and supplements EPA's zone map.

Radon in nearby counties

CountyEPA zoneLab tests4 pCi/L or more
Teton County, WYZone 114044.6%
Carbon County, MTZone 13452.2%
Hot Springs County, WYZone 13555.9%
Big Horn County, WYZone 15242.4%
Stillwater County, MTZone 14055.9%
Park County, MTZone 110060%

The six counties with the nearest centers.

What to do about radon in Park County

Test the building. EPA recommends fixing a home at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, and says there is no known safe level of exposure. Wyoming's state radon program can point you to testers and test kits.

Buying here? The Environmental Records Report lists this county's radon zone and test results with the flood zone, mapped faults, power lines and federal contamination records near the address.

Check one Park County address

Environmental Records Report, $29. PDF and JSON, usually ready in about a minute.

Radon in Park County: questions

What is the radon level in Park County?

The median of the 258 laboratory tests reported for Park County (2008 to 2017) was 3.4 pCi/L, and 42.8% of them were at or above 4 pCi/L. These are results of tested buildings; a single home can be far above or below them.

Is Park County in radon Zone 1?

Yes. EPA's 1993 Map of Radon Zones puts Park County in Zone 1, the counties with a predicted average indoor radon screening level above 4 pCi/L.

How does radon in Park County compare with Wyoming?

42.8% of laboratory tests in Park County were at or above 4 pCi/L for 2008 to 2017, against 43.1% across Wyoming (4,713 tests) and 36.5% nationally. 21 of Wyoming's 23 counties are in Zone 1.

Should I test for radon in Park County?

Yes. EPA recommends testing every home whatever its zone: "This map should not be used to determine if individual homes need to be tested." Fix the home at 4 pCi/L or more and consider a fix between 2 and 4 pCi/L; EPA says there is no known safe level of radon exposure.

More for Park County

Other free hazard lookups

All of these, plus wetlands, FEMA hazard ratings and the federal contamination lists, are in the Environmental Records Report for any US address ($29).

Radon in every Wyoming county · Radon map of every state

Data compiled 2026-10-20. County FIPS 56029. County-level screening information, not a radon measurement of any building.