Out of 355 ZIP codes with data in Montana, these are the lowest-ranked areas for radon zone. See also: National ZIP Codes in EPA Radon Zone 1 | All Montana Rankings
| Statistic | Value |
|---|---|
| ZIP codes ranked | 355 |
| Lowest value | Zone 1 (highest potential) |
| Median value | Zone 1 (highest potential) |
| State | Montana |
100 Lowest-Ranked ZIP Codes
| Rank | ZIP Code | City | State | Radon Zone | Safety Score |
|---|---|---|---|---|---|
| 1 | 59901 | Kalispell | MT | Zone 1 (highest potential) | 35/100 |
| 2 | 59602 | Helena | MT | Zone 1 (highest potential) | 50/100 |
| 3 | 59937 | Whitefish | MT | Zone 1 (highest potential) | 50/100 |
| 4 | 59601 | Helena | MT | Zone 1 (highest potential) | 51/100 |
| 5 | 59923 | Libby | MT | Zone 1 (highest potential) | 57/100 |
| 6 | 59912 | Columbia Falls | MT | Zone 1 (highest potential) | 59/100 |
| 7 | 59808 | Missoula | MT | Zone 1 (highest potential) | 60/100 |
| 8 | 59714 | Belgrade | MT | Zone 1 (highest potential) | 63/100 |
| 9 | 59860 | Polson | MT | Zone 1 (highest potential) | 63/100 |
| 10 | 59301 | Miles City | MT | Zone 1 (highest potential) | 65/100 |
| 11 | 59501 | Havre | MT | Zone 1 (highest potential) | 65/100 |
| 12 | 59801 | Missoula | MT | Zone 1 (highest potential) | 65/100 |
| 13 | 59330 | Glendive | MT | Zone 1 (highest potential) | 66/100 |
| 14 | 59457 | Lewistown | MT | Zone 1 (highest potential) | 66/100 |
| 15 | 59701 | Butte | MT | Zone 1 (highest potential) | 66/100 |
| 16 | 59715 | Bozeman | MT | Zone 1 (highest potential) | 66/100 |
| 17 | 59716 | Big Sky | MT | Zone 1 (highest potential) | 66/100 |
| 18 | 59718 | Bozeman | MT | Zone 1 (highest potential) | 66/100 |
| 19 | 59727 | Divide | MT | Zone 1 (highest potential) | 66/100 |
| 20 | 59802 | Missoula | MT | Zone 1 (highest potential) | 66/100 |
| 21 | 59803 | Missoula | MT | Zone 1 (highest potential) | 66/100 |
| 22 | 59270 | Sidney | MT | Zone 1 (highest potential) | 67/100 |
| 23 | 59725 | Dillon | MT | Zone 1 (highest potential) | 67/100 |
| 24 | 59812 | Missoula | MT | Zone 1 (highest potential) | 67/100 |
| 25 | 59834 | Frenchtown | MT | Zone 1 (highest potential) | 67/100 |
| 26 | 59840 | Hamilton | MT | Zone 1 (highest potential) | 67/100 |
| 27 | 59911 | Bigfork | MT | Zone 1 (highest potential) | 67/100 |
| 28 | 59001 | Absarokee | MT | Zone 1 (highest potential) | — |
| 29 | 59002 | Acton | MT | Zone 1 (highest potential) | — |
| 30 | 59003 | Ashland | MT | Zone 1 (highest potential) | — |
| 31 | 59004 | Ashland | MT | Zone 1 (highest potential) | — |
| 32 | 59007 | Bearcreek | MT | Zone 1 (highest potential) | — |
| 33 | 59008 | Belfry | MT | Zone 1 (highest potential) | — |
| 34 | 59012 | Birney | MT | Zone 1 (highest potential) | — |
| 35 | 59013 | Boyd | MT | Zone 1 (highest potential) | — |
| 36 | 59014 | Bridger | MT | Zone 1 (highest potential) | — |
| 37 | 59016 | Busby | MT | Zone 1 (highest potential) | — |
| 38 | 59018 | Clyde Park | MT | Zone 1 (highest potential) | — |
| 39 | 59019 | Columbus | MT | Zone 1 (highest potential) | — |
| 40 | 59020 | Cooke City | MT | Zone 1 (highest potential) | — |
| 41 | 59022 | Crow Agency | MT | Zone 1 (highest potential) | — |
| 42 | 59025 | Decker | MT | Zone 1 (highest potential) | — |
| 43 | 59026 | Edgar | MT | Zone 1 (highest potential) | — |
| 44 | 59027 | Emigrant | MT | Zone 1 (highest potential) | — |
| 45 | 59028 | Fishtail | MT | Zone 1 (highest potential) | — |
| 46 | 59029 | Fromberg | MT | Zone 1 (highest potential) | — |
| 47 | 59030 | Gardiner | MT | Zone 1 (highest potential) | — |
| 48 | 59031 | Garryowen | MT | Zone 1 (highest potential) | — |
| 49 | 59032 | Grass Range | MT | Zone 1 (highest potential) | — |
| 50 | 59034 | Hardin | MT | Zone 1 (highest potential) | — |
| 51 | 59035 | Fort Smith | MT | Zone 1 (highest potential) | — |
| 52 | 59041 | Joliet | MT | Zone 1 (highest potential) | — |
| 53 | 59043 | Lame Deer | MT | Zone 1 (highest potential) | — |
| 54 | 59047 | Livingston | MT | Zone 1 (highest potential) | — |
| 55 | 59050 | Lodge Grass | MT | Zone 1 (highest potential) | — |
| 56 | 59053 | Martinsdale | MT | Zone 1 (highest potential) | — |
| 57 | 59061 | Nye | MT | Zone 1 (highest potential) | — |
| 58 | 59062 | Otter | MT | Zone 1 (highest potential) | — |
| 59 | 59065 | Pray | MT | Zone 1 (highest potential) | — |
| 60 | 59066 | Pryor | MT | Zone 1 (highest potential) | — |
| 61 | 59067 | Rapelje | MT | Zone 1 (highest potential) | — |
| 62 | 59068 | Red Lodge | MT | Zone 1 (highest potential) | — |
| 63 | 59070 | Roberts | MT | Zone 1 (highest potential) | — |
| 64 | 59071 | Roscoe | MT | Zone 1 (highest potential) | — |
| 65 | 59077 | Sand Springs | MT | Zone 1 (highest potential) | — |
| 66 | 59081 | Silver Gate | MT | Zone 1 (highest potential) | — |
| 67 | 59084 | Teigen | MT | Zone 1 (highest potential) | — |
| 68 | 59086 | Wilsall | MT | Zone 1 (highest potential) | — |
| 69 | 59089 | Wyola | MT | Zone 1 (highest potential) | — |
| 70 | 59201 | Wolf Point | MT | Zone 1 (highest potential) | — |
| 71 | 59211 | Antelope | MT | Zone 1 (highest potential) | — |
| 72 | 59212 | Bainville | MT | Zone 1 (highest potential) | — |
| 73 | 59213 | Brockton | MT | Zone 1 (highest potential) | — |
| 74 | 59214 | Brockway | MT | Zone 1 (highest potential) | — |
| 75 | 59215 | Circle | MT | Zone 1 (highest potential) | — |
| 76 | 59217 | Crane | MT | Zone 1 (highest potential) | — |
| 77 | 59218 | Culbertson | MT | Zone 1 (highest potential) | — |
| 78 | 59219 | Dagmar | MT | Zone 1 (highest potential) | — |
| 79 | 59221 | Fairview | MT | Zone 1 (highest potential) | — |
| 80 | 59222 | Flaxville | MT | Zone 1 (highest potential) | — |
| 81 | 59223 | Fort Peck | MT | Zone 1 (highest potential) | — |
| 82 | 59225 | Frazer | MT | Zone 1 (highest potential) | — |
| 83 | 59226 | Froid | MT | Zone 1 (highest potential) | — |
| 84 | 59230 | Glasgow | MT | Zone 1 (highest potential) | — |
| 85 | 59231 | Saint Marie | MT | Zone 1 (highest potential) | — |
| 86 | 59240 | Glentana | MT | Zone 1 (highest potential) | — |
| 87 | 59241 | Hinsdale | MT | Zone 1 (highest potential) | — |
| 88 | 59242 | Homestead | MT | Zone 1 (highest potential) | — |
| 89 | 59243 | Lambert | MT | Zone 1 (highest potential) | — |
| 90 | 59244 | Larslan | MT | Zone 1 (highest potential) | — |
| 91 | 59247 | Medicine Lake | MT | Zone 1 (highest potential) | — |
| 92 | 59248 | Nashua | MT | Zone 1 (highest potential) | — |
| 93 | 59250 | Opheim | MT | Zone 1 (highest potential) | — |
| 94 | 59252 | Outlook | MT | Zone 1 (highest potential) | — |
| 95 | 59253 | Peerless | MT | Zone 1 (highest potential) | — |
| 96 | 59254 | Plentywood | MT | Zone 1 (highest potential) | — |
| 97 | 59255 | Poplar | MT | Zone 1 (highest potential) | — |
| 98 | 59256 | Raymond | MT | Zone 1 (highest potential) | — |
| 99 | 59257 | Redstone | MT | Zone 1 (highest potential) | — |
| 100 | 59258 | Reserve | MT | Zone 1 (highest potential) | — |
Methodology
This ranking is limited to EPA county-level radon zone classification. Zone 1 identifies the highest county-level potential category; it does not measure a home or establish whether any building is above an action level. Within Zone 1, ZIP codes are sub-ranked by Home Safety Score to organize area context.
Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-08-31.
Frequently Asked Questions
What is EPA Radon Zone 1?
Zone 1 is the EPA highest county-level radon-potential category. It is not a measurement for a home and cannot determine whether a building is above an action level. A home test is required for that decision.
Should I test for radon?
The EPA recommends testing all homes regardless of radon zone. A DIY test kit costs $15-40. Professional testing costs $150-250. If levels exceed 4 pCi/L, mitigation systems ($800-2,500) can reduce radon by up to 99%.
Explore More Rankings
- Worst ZIP Codes for Lead in Water in Montana
- ZIP Codes with Most EPA Violations in Montana
- Lowest Home Safety Scores in Montana
- Highest Home Safety Scores in Montana
- Historical NFIP Claim Counts in Montana
- ZIP Codes with Highest Energy Costs in Montana
- ZIP Codes with PFAS Detections in Montana
- Least Reliable Water Systems in Montana
- Environmental Justice Concern Areas in Montana
- Worst ZIP Codes for Homebuyers in Montana
- ZIP Codes with Worst CO & Gas Risk in Montana
- Safest ZIP Codes for Gas & CO Risk in Montana
- ZIP Codes with Worst Wildfire Smoke Risk in Montana
- Safest ZIP Codes for Wildfire Smoke in Montana
- All Rankings