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 Toole County, Montana
EPA puts Toole County in Zone 1, its highest radon zone, and only 11 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
Nearest county
35.0%
Hill County, 73 miles
- Hill
- 35.0%
- Montana
- 47.4%
Share at 4+ pCi/L, 120 tests, 2006 to 2015
Ground above low
100.0%
Level with Montana
- Toole
- 100.0%
- Montana
- 100.0%
Share of land USGS rates moderate or high potential
Tests reported
11
Too few for a share
- Toole
- 11
- Needed
- 30
2008 to 2017, 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 Toole 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
Toole County, At a glance
Toole County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Toole 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 Toole County, 2008 to 2017, laboratory
CDC holds 11 reported tests for Toole County over the 2008 to 2017 laboratory totals, with a median of 3.7 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Toole County beside the counties around it is how this page reads it.
What these figures count
Only 11 tests were reported to CDC for Toole 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).
Toole County, Compared
Toole County radon figures, compared
Calculated by Radon411CDC's largest figure for Toole County rests on 11 tests over the 2008 to 2017 laboratory totals, 5 of them at or above 4 pCi/L, so each test moves its share by 9.1 points and no rank or comparison is drawn from it. Results reached as high as 17.8 pCi/L, with a middle value of 3.7 pCi/L.
The nearest counties with a figure are Hill County (73 miles away) at 35.0%, Cascade County (94 miles away) at 35.9% and Lewis and Clark County (111 miles away) at 63.5%. 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 Toole 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.
Toole County, Geology
The ground under Toole County
PredictedUSGS's geologic map puts all of Toole County's mapped land in one class: high radon potential. 98.1% of it lies in the area the map calls Great Plains (Glaciated), 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 |
|---|---|---|---|---|
| Great Plains (Glaciated) | Glacial deposits derived from Cretaceous shales containing higher than average amounts of uranium. | High | 13 | 98.1% |
| Northern Rocky Mountains | Granitic, metaigneous, metasedimentary rocks, valley fill colluvium and alluvium. | High | 13 | 1.9% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Toole County beside the ground around it
Toole County has more high-potential ground than Montana as a whole: 100% of its land against 78.5%. Of the 3 counties that border it, none has as large a share of high-potential ground; Liberty County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Toole County, Local resources
Radon testing and mitigation in Toole 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
Toole County, Questions
Questions about radon in Toole County
Are radon levels high in Toole County?
Over the 2008 to 2017 laboratory totals, 45.5% of the radon tests reported to CDC for Toole County, Montana were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.7 pCi/L. Of the 8 nearest counties with a figure, within 152 miles, the share of tests at or above 4 pCi/L runs from 35.0% to 72.2%.
Which counties border Toole County?
Toole County borders 3 counties: Liberty County, Pondera County and Glacier County.
Products
Toole County, Products
Testing a home in Toole County
No CDC figure names Toole County; the nearest county with one, Hill County (73 miles away), reported 35.0% 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 Toole 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
MonitorX-Sense
XR0B-SR battery digital radon monitor with an alarm
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
Short-term kit
RA400 short-term liquid scintillation radon test kit, lab fee included
- Lab fee included
Method: Liquid scintillation
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Toole County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Toole County
Explore
Toole County, Bordering counties
Counties bordering Toole County
Calculated by Radon411- 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 Glacier CountyEPA zone 1
16.7%at or above 4 pCi/L
Median 2.7 pCi/L · 6 tests
- Radon levels in Pondera CountyEPA zone 1
0.0%at or above 4 pCi/L
Median 1.1 pCi/L · 5 tests
Toole County, Cities and towns
Cities and towns in Toole County
The Census Bureau estimates 5,211 residents in Toole County for July 1, 2025, 244 more than in 2020 (+4.9%). Spread over its land, that is 2.7 people to the square mile. Shelby alone is home to 3,313 of them, 63.6% of the total. Together its 3 incorporated places hold 73.6% of those residents; the other 26.4% live outside any of them. Reported testing is thin here: 11 tests over 2008 to 2017, or 2.1 for every 1,000 residents (2025 estimate), where Montana as a whole comes to 8.6.
From Shelby to Kevin, CDC publishes no figure by town: each reads Toole County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Shelby | 3,313 | +4.7% | 63.6% |
| Sunburst | 356 | +6.0% | 6.8% |
| Kevin | 164 | +5.1% | 3.1% |
3 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).
Toole County, Homes
Homes in Toole County
Of Toole County's 2,323 homes, 73% are detached houses, against 69% across Montana; 12% are in buildings of five or more homes. The homes are older than Montana's as a whole: half were built before 1969 (1980 for Montana), and 41% date from before 1960. 65% 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 | Toole County | Montana |
|---|---|---|
| Housing units | 2,323 | 522,939 |
| Detached houses | 73% | 69% |
| In buildings of 5 or more | 12% | 9% |
| Mobile homes | 10% | 10% |
| Built before 1960 | 41% | 26% |
| Built since 2000 | 15% | 27% |
| Middle year built | 1969 | 1980 |
| Owner-occupied | 65% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.