Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Lincoln County, Montana
EPA puts Lincoln County in Zone 1, its highest radon zone, and high results are common there: 51.4% of the 74 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
51.4%
5.9 pts above MT
- Lincoln
- 51.4%
- Montana
- 45.5%
74 tests, 2008 to 2017
Median result
4.0pCi/L
Action level reached
- Lincoln
- 4.0 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
74
12th of 23 by tests
- Lincoln
- 74
- Missoula
- 2,613
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Montana
13 of 23
Middle half
- Lincoln
- 51.4%
- Richland
- 78.6%
By share, of 23 with 30+ tests
Read a result for Lincoln County
Starts at Lincoln County's median, 4.0 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 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. Lincoln County's median reported result, 2008 to 2017.
The data
Lincoln County, At a glance
Lincoln County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Lincoln County in
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Lincoln County, 2008 to 2017, laboratory
Under 2 pCi/L: 27%2 to 4 pCi/L: 22%4 pCi/L and above: 51%
Of 74 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 20 | 27.0% |
| 2 to 4 pCi/L | 16 | 21.6% |
| 4 pCi/L and above | 38 | 51.4% |
What these figures count
These are the 74 tests reported to CDC for Lincoln 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).
Lincoln County, Compared
Lincoln County radon figures, compared
Calculated by Radon411More than half: 51.4% of the 74 radon tests reported to CDC for Lincoln County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 13th of 23 Montana counties with 30 or more tests for the same period. That is 5.9 points above the 45.5% pooled from 51 Montana counties.
The median result, 4.0 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 375.3 pCi/L. The rest split 27.0% under 2 pCi/L and 21.6% from 2 to 4 (Montana: 29.2% and 25.2%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 51.4% share point the same way here.
No bordering county with a figure for the same period reported a higher share; the closest is Sanders County at 50.0%, the lowest Boundary County, ID at 20.0%. Statewide for the same period, Richland County reported the highest share (78.6%) and Cascade County the lowest (29.4%).
CDC's ten-year totals for Lincoln County went from 58 tests (2005 to 2014) to 74 (2008 to 2017), the share going from 56.9% to 51.4%.
Nationally, every county with a figure for the same period pools to 35.7%; Lincoln County sits 15.7 points above it.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Lincoln County, Geology
The ground under Lincoln County
PredictedUSGS's geologic map puts all of Lincoln County's mapped land in one class: high radon potential. All of it lies in the area the map calls Northern Rocky Mountains, to which USGS gives a radon index of 13, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Northern Rocky Mountains | Granitic, metaigneous, metasedimentary rocks, valley fill colluvium and alluvium. | High | 13 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Lincoln County beside the ground around it
Lincoln County has more high-potential ground than Montana as a whole: 100% of its land against 78.5%. Of the 4 counties that border it, none has as large a share of high-potential ground; Flathead County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Lincoln County, Local resources
Radon testing and mitigation in Lincoln County
- Radon Control ProgramRadon Control Program, run by Montana DEQ, does not license radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Montana.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Energy Bureau staff manage the radon information toll-free hotline and distribute subsidized radon test kits to Montana residents.
- Compare kits
- See the Montana directoryNo professionals are listed in Montana yet. The state program can point you to registered testers and mitigators.
What Montana's program says
- Phone
- 1-800-546-0483
- Licensing of radon professionals
Montana DEQ does not certify or require proof of certification for the contractors listed.
What it means
Lincoln County, Questions
Questions about radon in Lincoln County
Are radon levels high in Lincoln County?
Over the 2008 to 2017 laboratory totals, 51.4% of the radon tests reported to CDC for Lincoln County, Montana were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.0 pCi/L. Of 23 Montana counties with 30 or more tests for the same period, 12 reported a higher share; pooled, the state comes to 45.5%.
Which counties border Lincoln County?
Lincoln County borders 4 counties: Boundary County, ID, Bonner County, ID, Sanders County, MT and Flathead County, MT.
Products
Lincoln County, Products
Testing a home in Lincoln County
In Lincoln County, 51.4% of 74 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 45.5% pooled across Montana. In Zone 1 the year-round level in Lincoln 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
MonitorAranet
Radon One battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 10 minutes
Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Lincoln County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Lincoln County
Explore
Lincoln County, Bordering counties
Counties bordering Lincoln County
Calculated by Radon411- Radon levels in Sanders County, MTEPA zone 1
50.0%at or above 4 pCi/L
Median 4.0 pCi/L · 38 tests · 1.4 points below Lincoln County
- Radon levels in Flathead County, MTEPA zone 1
37.8%at or above 4 pCi/L
Median 3.0 pCi/L · 891 tests · 13.6 points below Lincoln County
- Radon levels in Bonner County, IDEPA zone 1
33.0%at or above 4 pCi/L
Median 2.3 pCi/L · 321 tests · 18.4 points below Lincoln County
- Radon levels in Boundary County, IDEPA zone 1
20.0%at or above 4 pCi/L
Median 2.1 pCi/L · 45 tests · 31.4 points below Lincoln County
Lincoln County, Cities and towns
Cities and towns in Lincoln County
Lincoln County is growing: the Census Bureau puts it at 22,328 residents on July 1, 2025, up 13.1% from 19,737 in 2020. Spread over its land, that is 6.2 people to the square mile. No town dominates: Libby, the largest, has 3,274 residents, 14.7% of the total. Together its 4 incorporated places hold 26.2% of those residents; the other 73.8% live outside any of them. Reported testing is thin here: 74 tests over 2008 to 2017, or 3.3 for every 1,000 residents (2025 estimate), where Montana as a whole comes to 8.6.
From Libby to Rexford, CDC publishes no figure by town: each reads Lincoln County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Libby | 3,274 | +17.1% | 14.7% |
| Eureka | 1,562 | +12.5% | 7.0% |
| Troy | 916 | +15.2% | 4.1% |
| Rexford | 87 | +11.5% | 0.4% |
4 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).
Lincoln County, Homes
Homes in Lincoln County
Lincoln County is a place of houses on their own lots: 77% of its 10,991 homes are detached single-family houses, against 69% across Montana. Half of its homes were built before 1982, close to Montana's 1980: 19% date from before 1960 and 28% from 2000 or later. Owners live in 79% of the occupied homes (Montana: 69%), so for most households a test and a fix are their own to order.
| Homes | Lincoln County | Montana |
|---|---|---|
| Housing units | 10,991 | 522,939 |
| Detached houses | 77% | 69% |
| In buildings of 5 or more | 2% | 9% |
| Mobile homes | 15% | 10% |
| Built before 1960 | 19% | 26% |
| Built since 2000 | 28% | 27% |
| Middle year built | 1982 | 1980 |
| Owner-occupied | 79% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.