Out of 54 counties with earthquake data, these are the counties with the highest seismic risk.
| Statistic | Value |
|---|---|
| Counties ranked | 54 |
| Avg earthquake risk (top 100) | 2.7/50 |
Top 54 Counties
| Rank | County | State | Risk Score | Rating | Expected Annual Loss |
|---|---|---|---|---|---|
| 1 | Lake | Montana | 14.1/50 | Relatively Moderate | $2.9M |
| 2 | Flathead | Montana | 12.5/50 | Very Low | $6.6M |
| 3 | Missoula | Montana | 8.2/50 | Relatively Low | $2.9M |
| 4 | Silver Bow | Montana | 7/50 | Relatively Low | $762K |
| 5 | Glacier | Montana | 6.9/50 | Relatively Low | $122K |
| 6 | Lewis and Clark | Montana | 5.7/50 | Relatively Low | $1.0M |
| 7 | Lincoln | Montana | 5.6/50 | Relatively Low | $6.6M |
| 8 | Madison | Montana | 5.6/50 | Relatively Low | $762K |
| 9 | Sanders | Montana | 5.5/50 | Relatively Low | $182K |
| 10 | Gallatin | Montana | 4.8/50 | Relatively Low | $2.9M |
| 11 | Ravalli | Montana | 4.3/50 | Relatively Low | $142K |
| 12 | Park | Montana | 4.2/50 | Relatively Low | $245K |
| 13 | Beaverhead | Montana | 4.1/50 | Relatively Low | $237K |
| 14 | Powell | Montana | 3.5/50 | Very Low | $205K |
| 15 | Broadwater | Montana | 3.4/50 | Very Low | $349K |
| 16 | Jefferson | Montana | 3.3/50 | Very Low | $371K |
| 17 | Cascade | Montana | 3.3/50 | Very Low | $113K |
| 18 | Pondera | Montana | 3.3/50 | Very Low | $45K |
| 19 | Mineral | Montana | 3.1/50 | Very Low | $24K |
| 20 | Deer Lodge | Montana | 3/50 | Very Low | $53K |
| 21 | Yellowstone | Montana | 2.5/50 | Very Low | $205K |
| 22 | Granite | Montana | 2.4/50 | Very Low | $20K |
| 23 | Teton | Montana | 2.3/50 | Very Low | $45K |
| 24 | Meagher | Montana | 2.2/50 | Very Low | $11K |
| 25 | Sweet Grass | Montana | 2.1/50 | Very Low | $245K |
| 26 | Carbon | Montana | 2.1/50 | Very Low | $34K |
| 27 | Big Horn | Montana | 1.9/50 | Very Low | $5K |
| 28 | Toole | Montana | 1.7/50 | Very Low | $19K |
| 29 | Liberty | Montana | 1.4/50 | Very Low | $3K |
| 30 | Stillwater | Montana | 1.2/50 | Very Low | $21K |
| 31 | Custer | Montana | 1.1/50 | Very Low | $4K |
| 32 | Chouteau | Montana | 1.1/50 | Very Low | $3K |
| 33 | Roosevelt | Montana | 1.1/50 | Very Low | $1K |
| 34 | Rosebud | Montana | 1/50 | Very Low | $5K |
| 35 | Wheatland | Montana | 1/50 | Very Low | $2K |
| 36 | Hill | Montana | 0.9/50 | Very Low | $3K |
| 37 | Valley | Montana | 0.9/50 | Very Low | $2K |
| 38 | Treasure | Montana | 0.8/50 | Very Low | $97K |
| 39 | Fergus | Montana | 0.8/50 | Very Low | $3K |
| 40 | Judith Basin | Montana | 0.6/50 | Very Low | $3K |
| 41 | Musselshell | Montana | 0.5/50 | Very Low | $3K |
| 42 | Sheridan | Montana | 0.5/50 | Very Low | $781 |
| 43 | Blaine | Montana | 0.5/50 | Very Low | $453 |
| 44 | Phillips | Montana | 0.4/50 | Very Low | $478 |
| 45 | Powder River | Montana | 0.4/50 | Very Low | $419 |
| 46 | Carter | Montana | 0.4/50 | Very Low | $419 |
| 47 | Richland | Montana | 0.3/50 | Very Low | $1K |
| 48 | Daniels | Montana | 0.3/50 | Very Low | $781 |
| 49 | Golden Valley | Montana | 0.3/50 | Very Low | $480 |
| 50 | Garfield | Montana | 0.3/50 | Very Low | $223 |
| 51 | Dawson | Montana | 0.2/50 | Very Low | $547 |
| 52 | McCone | Montana | 0.2/50 | Very Low | $251 |
| 53 | Fallon | Montana | 0.2/50 | Very Low | $225 |
| 54 | Petroleum | Montana | 0.1/50 | Very Low | $70 |
* = New Madrid Seismic Zone
Methodology
County rankings for Montana based on average FEMA earthquake risk score.
Data sources: FEMA National Risk Index, USGS Earthquake Hazards Program. Last updated: 2026-06-04.
Frequently Asked Questions
How is earthquake risk calculated?
Earthquake risk scores (0-50) are from the FEMA National Risk Index, which combines seismic hazard exposure, community vulnerability, and expected losses. Higher scores indicate greater earthquake risk to people and property.
What is the New Madrid Seismic Zone?
The New Madrid Seismic Zone spans parts of Missouri, Tennessee, Arkansas, Kentucky, Illinois, Indiana, and Mississippi. The 1811-1812 New Madrid earthquakes (estimated M7.5-7.9) were among the strongest in U.S. history. This region remains seismically active, and most buildings were not designed to withstand major earthquakes.
Does earthquake risk affect home insurance?
Standard homeowners insurance does not cover earthquake damage. Separate earthquake insurance is required, and premiums vary significantly based on location, construction type, and proximity to fault lines.