Stillwater County, Montana Natural Disaster Risk
FEMA National Risk Index assessment · MT
Very LowComposite Risk Score
National percentile: 17th
Stillwater County faces very low composite natural disaster risk (NRI Risk Index score 16.8, 17th national percentile), driven primarily by wildfire and avalanche exposure. Expected annual loss across all 18 hazard types is $9M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Stillwater County is very low, with a National Risk Index score of 16.8 out of 100 — placing it in the 17th national percentile and among the lowest-risk counties in the country. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $1M in expected annual loss and about 0.00 events per year; avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Very Low risk — $2K in expected annual loss and about 0.13 events per year; and landslide (downhill movement of rock, soil, and debris on unstable slopes) at Very Low risk — $3K in expected annual loss and about 1.39 events per year. Across all hazards, FEMA estimates $9M in expected annual loss for a population of 9K.
Beyond physical exposure, Stillwater County has a very low social vulnerability rating (how susceptible the population is to harm) and a medium community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
The county's disaster history tells the same story: Stillwater County has received 16 federal disaster declarations since 1978, including 5 for flood events and 5 for fire events. The most recent was Severe Winter Storm and Straight-Line Winds (straight-line winds), declared in April 2026.
Among 56 Montana counties, Stillwater County ranks #35 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Wildfire | Low | 0.00 / yr | $1M |
| Avalanche | Very Low | 0.13 / yr | $2K |
| Landslide | Very Low | 1.39 / yr | $3K |
| Winter Weather | Low | 21.59 / yr | $96K |
| Cold Wave | Low | 2.72 / yr | $1M |
| Lightning | Low | 35.26 / yr | $226K |
| Riverine Flood | Low | 0.61 / yr | $6M |
| Earthquake | Very Low | 0.00 / yr | $144K |
| Hail | Very Low | 1.61 / yr | $158K |
| Drought | Very Low | 68.91 / yr | $19K |
| Heat Wave | Very Low | 1.19 / yr | $45K |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
| Tornado | Very Low | 0.07 / yr | $44K |
| Strong Wind | Very Low | 0.70 / yr | $56K |
| Ice Storm | Very Low | 0.01 / yr | $4K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Stillwater County has received 16 federal disaster declarations since 1978, most recently Severe Winter Storm and Straight-Line Winds in April 2026. Most frequent causes: Flood (5), Fire (5), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2026 | Straight-Line Winds | Severe Winter Storm and Straight-Line Winds |
| October 2023 | Flood | Flooding |
| June 2022 | Flood | Severe Storm and Flooding |
| August 2020 | Fire | Falling Star Fire |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| May 2019 | Flood | Flooding |
| April 2014 | Flood | Ice Jams and Flooding |
| June 2011 | Severe Storm | Severe Storms and Flooding |
| September 2009 | Fire | Eagle Mount Fire |
Showing the 10 most recent of 16 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Stillwater County?
Stillwater County has a composite FEMA National Risk Index score of 16.8 out of 100, placing it in the Very Low category and the 17th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Stillwater County?
The three highest-rated hazards are Wildfire (Low, $1M EAL), Avalanche (Very Low, $2K EAL), Landslide (Very Low, $3K EAL). These account for most of the county's expected annual losses.
How does Stillwater County compare to other Montana counties?
Stillwater County ranks #35 of 56 Montana counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Stillwater County had?
FEMA records 16 federal disaster declarations for Stillwater County since 1978, most often 5 for flood events and 5 for fire events. The most recent was Severe Winter Storm and Straight-Line Winds, declared in April 2026.
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. Stillwater County's $9M EAL is a statistical average, not a guarantee for any specific year or address.