Short-term kit
Radon Short Term Test Kit short-term charcoal radon test kit, lab fee included
- Lab fee included
Method: Charcoal
In home: 2 to 7 days
Locations and reports
Radon Levels in Bear Lake County, Idaho
EPA puts Bear Lake County in Zone 2, its middle radon zone, and high results are common there: 78.1% of the 32 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
Share at 4+ pCi/L
78.1%
36.6 pts above ID
- Bear Lake
- 78.1%
- Idaho
- 41.5%
32 tests, 2008 to 2017
Median result
7.8pCi/L
Action level reached
- Bear Lake
- 7.8 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
32
35th of 37 by tests
- Bear Lake
- 32
- Ada
- 3,030
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in Idaho
1 of 37
Top quarter
- Bear Lake
- 78.1%
- Bear Lake
- 78.1%
By share, of 37 with 30+ tests
Read a result for Bear Lake County
Starts at Bear Lake County's median, 7.8 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 7.8 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 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. Bear Lake County's median reported result, 2008 to 2017.
The data
Bear Lake County, At a glance
Bear Lake County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Bear Lake County is a
USGS geologic potential: Moderate across 97% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Bear Lake County, 2008 to 2017, laboratory
Under 2 pCi/L: 9%2 to 4 pCi/L: 13%4 pCi/L and above: 78%
Of 32 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 3 | 9.4% |
| 2 to 4 pCi/L | 4 | 12.5% |
| 4 pCi/L and above | 25 | 78.1% |
What these figures count
These are the 32 tests reported to CDC for Bear Lake 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).
Bear Lake County, Compared
Bear Lake County radon figures, compared
Calculated by Radon411More than half: 78.1% of the 32 radon tests reported to CDC for Bear Lake County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 1st of 37 Idaho counties with 30 or more tests for the same period. That is 36.6 points above the 41.5% pooled from 44 Idaho counties.
The median result, 7.8 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 29.0 pCi/L. The rest split 9.4% under 2 pCi/L and 12.5% from 2 to 4 (Idaho: 31.5% and 26.9%). The reported tests do not follow EPA's Zone 2 label for Bear Lake County (predicted average between 2 and 4 pCi/L): 78.1% of them reached 4 pCi/L, fewer than that label suggests.
No bordering county with a figure for the same period reported a higher share; the closest is Lincoln County, WY at 68.3%, the lowest Franklin County at 34.7%. Statewide for the same period, Custer County reported the highest share (72.7%) and Payette County the lowest (4.9%).
CDC's ten-year totals for Bear Lake County went from 47 tests (2005 to 2014) to 32 (2008 to 2017), the share going from 72.3% to 78.1%.
Nationally, every county with a figure for the same period pools to 35.7%; Bear Lake County sits 42.4 points above it.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Bear Lake County, Geology
The ground under Bear Lake County
PredictedMost of the ground under Bear Lake County is one class on USGS's geologic map: 96.7% of its land is moderate radon potential, with 3.3% high. The map puts 65.7% of Bear Lake County in the area it calls Middle Rocky Mountain province and 31.0% in Basin and Range, with one smaller area beside them. USGS gives both a radon index of 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Middle Rocky Mountain province | Complexly folded, faulted, and metamorphosed rocks of volcanic origin. | Moderate | 11 | 65.7% |
| Basin and Range | Cenozoic to Paleozoic sedimentary rocks. | Moderate | 11 | 31.0% |
| Northern Rocky Mountains | Tertiary sandstone, mudstone, limestone. | High | 13 | 3.3% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Bear Lake County beside the ground around it
Idaho as a whole has more high-potential ground than Bear Lake County: 50.7% of its land, against 3.3% here. Of the 5 counties that border it, 4 have more high-potential ground, Rich County, UT the most at 66.7%.
The map rates the ground, not the air in any home.
Local help
Bear Lake County, Local resources
Radon testing and mitigation in Bear Lake County
- DHW Environmental Health ProgramDHW Environmental Health Program, run by Idaho Department of Health and Welfare, offers free or discounted test kits, and answers questions about testing and mitigation in Idaho.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Order a free radon test kit.
- Compare kits
- See the Idaho directoryNo professionals are listed in Idaho yet. The state program can point you to registered testers and mitigators.
What Idaho's program says
- Phone
- 800-445-8647
- radon@dhw.idaho.gov
What it means
Bear Lake County, Questions
Questions about radon in Bear Lake County
Are radon levels high in Bear Lake County?
Over the 2008 to 2017 laboratory totals, 78.1% of the radon tests reported to CDC for Bear Lake County, Idaho were at or above 4 pCi/L, and the median reported pre-mitigation result was 7.8 pCi/L. Of 37 Idaho counties with 30 or more tests for the same period, none reported a higher share; pooled, the state comes to 41.5%.
Which counties border Bear Lake County?
Bear Lake County borders 5 counties: Lincoln County, WY, Franklin County, ID, Caribou County, ID, Cache County, UT and Rich County, UT.
Products
Bear Lake County, Products
Testing a home in Bear Lake County
In Bear Lake County, 78.1% of 32 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 41.5% pooled across Idaho. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Bear Lake County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Monitor
Corentium Home battery digital radon detector
- C-NRPP 2024/25: Approved
- Battery
- Screen
Method: Alpha spectrometry
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Bear Lake County, Bordering counties
Counties bordering Bear Lake County
Calculated by Radon411- Radon levels in Lincoln County, WYEPA zone 1
68.3%at or above 4 pCi/L
Median 7.8 pCi/L · 142 tests · 9.8 points below Bear Lake County
- Radon levels in Cache County, UTEPA zone 2
56.8%at or above 4 pCi/L
Median 4.7 pCi/L · 1,339 tests · 21.3 points below Bear Lake County
- Radon levels in Caribou County, IDEPA zone 2
43.9%at or above 4 pCi/L
Median 3.4 pCi/L · 57 tests · 34.2 points below Bear Lake County
- Radon levels in Franklin County, IDEPA zone 2
34.7%at or above 4 pCi/L
Median 3.1 pCi/L · 75 tests · 43.4 points below Bear Lake County
- Radon levels in Rich County, UTEPA zone 2
0.0%at or above 4 pCi/L
Median 1.4 pCi/L · 2 tests · 78.1 points below Bear Lake County
Bear Lake County, Cities and towns
Cities and towns in Bear Lake County
Bear Lake County is growing: the Census Bureau puts it at 6,727 residents on July 1, 2025, up 5.7% from 6,365 in 2020. Spread over its land, that is 6.9 people to the square mile. Its largest town, Montpelier, has 2,710 residents, 40.3% of the total. Together its 5 incorporated places hold 61.5% of those residents; the other 38.5% live outside any of them. CDC's 32 reported tests for 2008 to 2017 work out to 4.8 per 1,000 residents (2025 estimate), close to Idaho's 6.4.
From Montpelier to St. Charles, CDC publishes no figure by town: each reads Bear Lake County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Montpelier | 2,710 | +2.6% | 40.3% |
| Paris | 541 | +0.2% | 8.0% |
| Georgetown | 492 | −1.8% | 7.3% |
| Bloomington | 212 | +7.1% | 3.2% |
| St. Charles | 185 | +12.1% | 2.8% |
5 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).
Bear Lake County, Homes
Homes in Bear Lake County
Bear Lake County is a place of houses on their own lots: 92% of its 3,943 homes are detached single-family houses, against 74% across Idaho. The homes are older than Idaho's as a whole: half were built before 1971 (1990 for Idaho), and 43% date from before 1960. Owners live in 85% of the occupied homes (Idaho: 72%), so for most households a test and a fix are their own to order.
| Homes | Bear Lake County | Idaho |
|---|---|---|
| Housing units | 3,943 | 776,683 |
| Detached houses | 92% | 74% |
| In buildings of 5 or more | 2% | 9% |
| Mobile homes | 5% | 7% |
| Built before 1960 | 43% | 18% |
| Built since 2000 | 21% | 35% |
| Middle year built | 1971 | 1990 |
| Owner-occupied | 85% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.