Gallatin County, Montana Natural Disaster Risk
FEMA National Risk Index assessment · MT
MediumComposite Risk Score
National percentile: 81th
Gallatin County faces medium composite natural disaster risk (NRI Risk Index score 81.0, 81th national percentile), driven primarily by winter weather and avalanche exposure. Expected annual loss across all 18 hazard types is $66M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Gallatin County at medium composite risk, with a National Risk Index score of 81.0 out of 100 — placing it in the 81st national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by winter weather (heavy snow, blizzards, and hazardous winter conditions) at Very High risk — $4M in expected annual loss and about 49.27 events per year; avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Very High risk — $7M in expected annual loss and about 0.67 events per year; and landslide (downhill movement of rock, soil, and debris on unstable slopes) at Medium risk — $352K in expected annual loss and about 2.58 events per year. Across all hazards, FEMA estimates $66M in expected annual loss for a population of 119K.
Beyond physical exposure, Gallatin County has a very low social vulnerability rating (how susceptible the population is to harm) and a high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
The federal record bears this out: Gallatin County has received 9 federal disaster declarations since 1981, including 3 for fire events and 2 for biological events. The most recent was Bridger Foothills Fire (fire), declared in September 2020.
Among 56 Montana counties, Gallatin County ranks #4 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Winter Weather | Very High | 49.27 / yr | $4M |
| Avalanche | Very High | 0.67 / yr | $7M |
| Landslide | Medium | 2.58 / yr | $352K |
| Earthquake | Medium | 0.06 / yr | $17M |
| Cold Wave | High | 3.57 / yr | $14M |
| Lightning | High | 37.00 / yr | $2M |
| Wildfire | Medium | 0.00 / yr | $3M |
| Hail | Medium | 0.51 / yr | $2M |
| Riverine Flood | Low | 0.43 / yr | $16M |
| Strong Wind | Low | 0.44 / yr | $605K |
| Drought | Low | 70.99 / yr | $78K |
| Heat Wave | Very Low | 0.29 / yr | $186K |
| Ice Storm | Very Low | 0.01 / yr | $34K |
| Volcanic Activity | Very Low | 0.00 / yr | $1 |
| Tornado | Very Low | 0.06 / yr | $259K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Gallatin County has received 9 federal disaster declarations since 1981, most recently Bridger Foothills Fire in September 2020. Most frequent causes: Fire (3), Biological (2), Severe Storm (2).
| Declared | Type | Disaster |
|---|---|---|
| September 2020 | Fire | Bridger Foothills Fire |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| July 2001 | Severe Storm | Severe Winter Storms |
| August 2000 | Fire | Wildfires |
| August 2000 | Fire | Mt - South Central Zone 4 Fire Complex |
| February 1996 | Severe Storm | Severe Storms, Flooding, and Ice Jams |
| May 1981 | Flood | Severe Storms & Flooding |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Gallatin County?
Gallatin County has a composite FEMA National Risk Index score of 81.0 out of 100, placing it in the Medium category and the 81th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Gallatin County?
The three highest-rated hazards are Winter Weather (Very High, $4M EAL), Avalanche (Very High, $7M EAL), Landslide (Medium, $352K EAL). These account for most of the county's expected annual losses.
How does Gallatin County compare to other Montana counties?
Gallatin County ranks #4 of 56 Montana counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Gallatin County had?
FEMA records 9 federal disaster declarations for Gallatin County since 1981, most often 3 for fire events and 2 for biological events. The most recent was Bridger Foothills Fire, declared in September 2020.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Gallatin County's $66M EAL is a statistical average, not a guarantee for any specific year or address.