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 Pondera County, Montana
EPA puts Pondera County in Zone 1, its highest radon zone, and only 5 radon tests from it are on file with CDC (2008 to 2017, laboratory totals). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Highest bordering
38.0%
Flathead County
- Flathead
- 38.0%
1 of 6 neighbours have 30+ tests, 2006 to 2015
Nearest county
35.9%
Cascade County, 76 miles
- Cascade
- 35.9%
- Montana
- 47.4%
Share at 4+ pCi/L, 284 tests, 2006 to 2015
Ground above low
100.0%
Level with Montana
- Pondera
- 100.0%
- Montana
- 100.0%
Share of land USGS rates moderate or high potential
Tests reported
9
Too few for a share
- Pondera
- 9
- Needed
- 30
2005 to 2014, laboratory
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Read a result for Pondera County
Starts at EPA's action level
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.
The data
Pondera County, At a glance
Pondera County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Pondera 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 Pondera County, 2008 to 2017, laboratory
CDC holds 5 reported tests for Pondera County over the 2008 to 2017 laboratory totals, with a median of 1.1 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Pondera County beside the counties around it is how this page reads it.
What these figures count
Only 5 tests were reported to CDC for Pondera County over 2008 to 2017 (laboratory totals), and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Pondera County, Compared
Pondera County radon figures, compared
Calculated by Radon411CDC's largest figure for Pondera County rests on 9 tests over the 2005 to 2014 laboratory totals, 2 of them at or above 4 pCi/L, so each test moves its share by 11.1 points and no rank or comparison is drawn from it. Results reached as high as 6.6 pCi/L, with a middle value of 1.7 pCi/L.
Flathead County, the one bordering county with a figure over the 2006 to 2015 laboratory totals, reported 38.0% of its tests at or above 4 pCi/L. Farther out, Cascade County (76 miles away) at 35.9%, Lewis and Clark County (77 miles away) at 63.5% and Lake County (95 miles away) at 38.0% have figures too. Pooled across 52 Montana counties, 47.4% of reported tests reached that level; across every county in the country with a figure, 36.3%.
Statewide for the same period, Sheridan County reported the highest share (75.7%) and Hill County the lowest (35.0%). EPA's 1993 map puts Pondera County in Zone 1, the map's highest label: a predicted county average above 4 pCi/L. USGS geology rates 100% of the county's land high radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Pondera County, Geology
The ground under Pondera County
PredictedUSGS's geologic map puts all of Pondera County's mapped land in one class: high radon potential. The map puts 52.7% of Pondera County in the area it calls Great Plains (Glaciated) and 47.3% in Northern Rocky Mountains. USGS gives both 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 |
|---|---|---|---|---|
| Great Plains (Glaciated) | Glacial deposits derived from Cretaceous shales containing higher than average amounts of uranium. | High | 13 | 52.7% |
| Northern Rocky Mountains | Granitic, metaigneous, metasedimentary rocks, valley fill colluvium and alluvium. | High | 13 | 47.3% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Pondera County beside the ground around it
Pondera County has more high-potential ground than Montana as a whole: 100% of its land against 78.5%. Of the 6 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
Pondera County, Local resources
Radon testing and mitigation in Pondera 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
Pondera County, Questions
Questions about radon in Pondera County
Are radon levels high in Pondera County?
Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Pondera County, Montana were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.1 pCi/L. Flathead County, the one bordering county with a figure over the 2006 to 2015 laboratory totals, reported 38.0% of its tests at or above 4 pCi/L.
Which counties border Pondera County?
Pondera County borders 6 counties: Teton County, Glacier County, Toole County, Liberty County, Flathead County and Chouteau County.
Products
Pondera County, Products
Testing a home in Pondera County
No CDC figure names Pondera County; the nearest county with one, Cascade County (76 miles away), reported 35.9% of its tests at or above 4 pCi/L over the 2006 to 2015 laboratory totals, the only reading nearby until a test of this home. In Zone 1 the year-round level in Pondera 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
Pondera County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Pondera County
Explore
Pondera County, Bordering counties
Counties bordering Pondera County
Calculated by Radon411- Radon levels in Chouteau CountyEPA zone 1
58.3%at or above 4 pCi/L
Median 5.1 pCi/L · 12 tests
- Radon levels in Flathead CountyEPA zone 1
38.0%at or above 4 pCi/L
Median 2.8 pCi/L · 924 tests
- Radon levels in Toole CountyEPA zone 1
33.3%at or above 4 pCi/L
Median 3.4 pCi/L · 6 tests
- Radon levels in Liberty CountyEPA zone 1
33.3%at or above 4 pCi/L
Median 3.8 pCi/L · 3 tests
- Radon levels in Teton CountyEPA zone 1
22.2%at or above 4 pCi/L
Median 2.9 pCi/L · 9 tests
- Radon levels in Glacier CountyEPA zone 1
16.7%at or above 4 pCi/L
Median 2.7 pCi/L · 6 tests
Pondera County, Cities and towns
Cities and towns in Pondera County
The Census Bureau estimates 6,072 residents in Pondera County for July 1, 2025, 189 more than in 2020 (+3.2%). Spread over its land, that is 3.7 people to the square mile. Its largest town, Conrad, has 2,393 residents, 39.4% of the total. Together its 2 incorporated places hold 48.3% of those residents; the other 51.7% live outside any of them. Reported testing is thin here: 9 tests over 2005 to 2014, or 1.5 for every 1,000 residents (2025 estimate), where Montana as a whole comes to 6.7.
From Conrad to Valier, CDC publishes no figure by town: each reads Pondera County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Conrad | 2,393 | +3.1% | 39.4% |
| Valier | 537 | +3.1% | 8.8% |
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).
Pondera County, Homes
Homes in Pondera County
Of Pondera County's 2,753 homes, 74% are detached houses, against 69% across Montana; 12% are mobile homes. The homes are older than Montana's as a whole: half were built before 1964 (1980 for Montana), and 46% date from before 1960. 67% of occupied homes are lived in by their owner (Montana: 69%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Pondera County | Montana |
|---|---|---|
| Housing units | 2,753 | 522,939 |
| Detached houses | 74% | 69% |
| In buildings of 5 or more | 8% | 9% |
| Mobile homes | 12% | 10% |
| Built before 1960 | 46% | 26% |
| Built since 2000 | 12% | 27% |
| Middle year built | 1964 | 1980 |
| Owner-occupied | 67% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.