Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Montrose County, Colorado
EPA puts Montrose County in Zone 1, its highest radon zone, and high results are common there: 55.3% of the 215 radon tests reported to CDC (2023) 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
55.3%
16.4 pts above CO
- Montrose
- 55.3%
- Colorado
- 38.9%
215 tests, 2023
Median result
4.5pCi/L
Action level reached
- Montrose
- 4.5 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
215
17th of 38 by tests
- Montrose
- 215
- Jefferson
- 3,068
Reported to CDC before any fix, 2023
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Colorado
4 of 38
Top quarter
- Montrose
- 55.3%
- Park
- 57.5%
By share, of 38 with 30+ tests
Read a result for Montrose County
Starts at Montrose County's median, 4.5 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.5 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. Montrose County's median reported result, 2023.
The data
Montrose County, At a glance
Montrose County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Montrose 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 Montrose County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 55.2% |
| 2015 | 73.0% |
| 2016 | 63.3% |
| 2017 | 51.9% |
| 2018 | 56.4% |
| 2019 | 66.6% |
| 2020 | 46.6% |
| 2021 | 48.6% |
| 2022 | 52.2% |
| 2023 | 55.3% |
2023: 55.3%. Across these years the share ran from 46.6% to 73.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 215 tests reported to CDC for Montrose County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Montrose County, Compared
Montrose County radon figures, compared
Calculated by Radon411More than half: 55.3% of the 215 radon tests reported to CDC for Montrose County in 2023 read at least 4 pCi/L. That places it 4th of 38 Colorado counties with 30 or more tests for the same period. That is 16.4 points above the 38.9% pooled from 61 Colorado counties.
The median result, 4.5 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 51.1 pCi/L. The rest split 23.7% under 2 pCi/L and 20.9% from 2 to 4 (Colorado: 39.2% and 22.0%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 55.3% share point the same way here.
1 of its 5 bordering counties with figures ran higher, led by Delta County at 55.6%; Mesa County reported 18.9%. Statewide for the same period, Park County reported the highest share (57.5%) and Bent County the lowest (3.7%).
The busiest year on file was 2019, with 479 tests reported; the quietest, 2015, had 74.
Over 10 years of annual figures the share held within 2 points, from 55.2% in 2014 to 55.3% in 2023; its peak was 73.0% in 2015. Nationally, every county with a figure for the same period pools to 33.4%; Montrose County sits 21.9 points above it. CDC also counts 19 tests taken after mitigation in Montrose County for the same period: tests in homes where a fix was already in.
Montrose CountyColorado, pooled
55.3% % of tests38.9% % of tests
| Year | Tests | Montrose County, at or above 4 pCi/L | Colorado, pooled |
|---|---|---|---|
| 2014 | 145 | 55.2% | 46.5% |
| 2015 | 74 | 73.0% | 47.2% |
| 2016 | 79 | 63.3% | 38.5% |
| 2017 | 104 | 51.9% | 41.0% |
| 2018 | 365 | 56.4% | 44.2% |
| 2019 | 479 | 66.6% | 44.1% |
| 2020 | 307 | 46.6% | 41.9% |
| 2021 | 148 | 48.6% | 47.3% |
| 2022 | 136 | 52.2% | 38.6% |
| 2023 | 215 | 55.3% | 38.9% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Montrose County, State data
Colorado's own radon test data
MeasuredWhat Colorado's own agencies publish about radon tests in Montrose County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What Colorado CDPHE reports for Montrose County
Radon data (county results): radon test results received from radon testing labs, primarily short-term household tests taken by the homeowner. Period: 2005-2025.
Share over 4 pCi/L
55.2%
1,376 of 2,491 tests
Median result
4.5 pCi/L
Highest result
361.7 pCi/L
Tests behind these figures
2,491 tests
- CDPHE says these data do not give actual radon levels in homes that have not been tested.
- When possible, only tests conducted before a mitigation system was installed are used.
- Some counties have very small numbers of test results, and their summaries may be less representative.
- These figures describe tests reported to Colorado CDPHE in this area. They count a different set of tests than CDC's figures and are not a reading of any one home.
Measured: Colorado CDPHE data, 2005-2025.
Montrose County, Geology
The ground under Montrose County
PredictedUSGS's geologic map puts all of Montrose County's mapped land in one class: high radon potential. The map puts 70.9% of Montrose County in the area it calls Uravan Belt and 28.9% in Mancos Shale Lowlands. 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 |
|---|---|---|---|---|
| Uravan Belt | Uranium-bearing Cretaceous and Jurassic sedimentary rocks of the Uravan mineral belt. | High | 13 | 70.9% |
| Mancos Shale Lowlands | Marine shales (Mancos Shale) and Tertiary sandstones. | High | 13 | 28.9% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Montrose County beside the ground around it
Montrose County has more high-potential ground than Colorado as a whole: 100% of its land against 74.8%. Of the 7 counties that border it, none has as large a share of high-potential ground; Delta County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Montrose County, Local resources
Radon testing and mitigation in Montrose County
- Colorado's radon programColorado Department of Public Health and EnvironmentColorado's radon program licenses or certifies radon professionals, offers free or discounted test kits and states the rule for disclosing radon when a home is sold, and answers questions about testing and mitigation in Colorado.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Order a discounted radon test kit
- Compare kits
- Professionals in Colorado25 professionals are listed in Colorado.
What Colorado's program says
- Licensing of radon professionals
Listed contractors are certified by the National Radon Proficiency Program or the National Radon Safety Board, and must be licensed by the Colorado Department of Regulatory Agencies.
- Disclosure when a home is sold or rented
As of August 7, 2023, landlords in Colorado are required to disclose radon information when a tenant signs a lease agreement.
What it means
Montrose County, Questions
Questions about radon in Montrose County
Are radon levels high in Montrose County?
In 2023, 55.3% of the radon tests reported to CDC for Montrose County, Colorado were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.5 pCi/L. Of 38 Colorado counties with 30 or more tests for the same period, 3 reported a higher share; pooled, the state comes to 38.9%.
Which counties border Montrose County?
Montrose County borders 7 counties: San Miguel County, CO, Ouray County, CO, Mesa County, CO, Delta County, CO, Gunnison County, CO, Grand County, UT and San Juan County, UT.
Products
Montrose County, Products
Testing a home in Montrose County
In Montrose County, 55.3% of 215 tests reported to CDC in 2023 reached 4 pCi/L, against 38.9% pooled across Colorado. In Zone 1 the year-round level in Montrose 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
Monitor
RadonPro Wi-Fi radon monitor with a built-in Geiger counter
- C-NRPP 2024/25: Not included
- Plug-in
- Wi-Fi
- Alarm
- Screen, app
First reading: Within 5 minutes
Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Montrose County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Montrose County
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Montrose County, Bordering counties
Counties bordering Montrose County
Calculated by Radon411- Radon levels in Delta County, COEPA zone 1
55.6%at or above 4 pCi/L
Median 4.6 pCi/L · 124 tests · 0.3 points above Montrose County
- Radon levels in San Juan County, UTEPA zone 2
52.6%at or above 4 pCi/L
Median 4.0 pCi/L · 19 tests · 2.7 points below Montrose County
- Radon levels in San Miguel County, COEPA zone 1
37.5%at or above 4 pCi/L
Median 3.4 pCi/L · 16 tests · 17.8 points below Montrose County
- Radon levels in Ouray County, COEPA zone 1
37.2%at or above 4 pCi/L
Median 1.2 pCi/L · 43 tests · 18.1 points below Montrose County
- Radon levels in Gunnison County, COEPA zone 1
34.7%at or above 4 pCi/L
Median 2.5 pCi/L · 147 tests · 20.6 points below Montrose County
- Radon levels in Grand County, UTEPA zone 1
23.9%at or above 4 pCi/L
Median 1.9 pCi/L · 46 tests · 31.4 points below Montrose County
- Radon levels in Mesa County, COEPA zone 1
18.9%at or above 4 pCi/L
Median 2.2 pCi/L · 567 tests · 36.4 points below Montrose County
Montrose County, Cities and towns
Cities and towns in Montrose County
The Census Bureau estimates 44,591 residents in Montrose County for July 1, 2025, 1,766 more than in 2020 (+4.1%). That works out to 20 people per square mile of land. Its largest town, Montrose, has 21,583 residents, 48.4% of the total. Together its 4 incorporated places hold 55.1% of those residents; the other 44.9% live outside any of them. CDC's 215 reported tests for 2023 work out to 4.8 per 1,000 residents (2025 estimate), close to Colorado's 3.6.
From Montrose to Naturita, CDC publishes no figure by town: each reads Montrose County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Montrose | 21,583 | +5.8% | 48.4% |
| Olathe | 1,927 | −3.7% | 4.3% |
| Nucla | 577 | −2.4% | 1.3% |
| Naturita | 478 | −1.2% | 1.1% |
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).
Montrose County, Homes
Homes in Montrose County
Of Montrose County's 19,429 homes, 67% are detached houses, against 62% across Colorado; 20% are mobile homes. Half of its homes were built before 1991, close to Colorado's 1987: 15% date from before 1960 and 34% from 2000 or later. 75% of occupied homes are lived in by their owner (Colorado: 66%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Montrose County | Colorado |
|---|---|---|
| Housing units | 19,429 | 2,545,124 |
| Detached houses | 67% | 62% |
| In buildings of 5 or more | 4% | 22% |
| Mobile homes | 20% | 4% |
| Built before 1960 | 15% | 16% |
| Built since 2000 | 34% | 31% |
| Middle year built | 1991 | 1987 |
| Owner-occupied | 75% | 66% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.