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Interstate 15
Fatal crashes 2015–2024 61Deaths 65Counties 9Latest data year 2024
FARS data are based on police crash reports and other sources; the drunk-driving measure is based on the highest BAC of any driver in the crash. Latest data year: 2024. The route is the trafficway recorded for each crash (FARS TWAY_ID); the same route number in another state has its own page.
Between 2015 and 2024, FARS records 61 fatal crashes on Interstate 15 in Montana, with 65 deaths.
That is 3.3% of the 1,864 fatal crashes in Montana over the same years. The ten-year crash count fell 6% from 65 in 2005–2014 to 61 in 2015–2024.
The crashes were concentrated in Cascade County (15), Beaverhead County (10) and Silver Bow County (10) and 6 other counties.
24.6% of the crashes had a driver reported as drinking (Montana: 43.9%) and 29.5% had a speeding-related driver (35.8%); pedestrians were 6.2% and motorcyclists 12.3% of those killed.
Fatal crashes per year
Route identification in FARS is consistent from 2000; earlier years are not shown. Shaded band: the ten-year window used for the shares below.
Compared with all fatal crashes in Montana
| Measure | Interstate 15 | Montana |
|---|---|---|
| Fatal crashes, 2015–2024 | 61 | 1,864 |
| Deaths, 2015–2024 | 65 | 2,046 |
| Deaths per fatal crash | 1.1 | 1.1 |
| Share of state fatal crashes | 3.3% | 100% |
| Change vs previous ten years | -6% | -8% |
Factor shares
Counties along the route
| # | County | Fatal crashes on I-15 | Share of route | County total, all roads |
|---|---|---|---|---|
| 1 | Cascade County | 15 | 25% | 91 |
| 2 | Beaverhead County | 10 | 16% | 31 |
| 3 | Silver Bow County | 10 | 16% | 34 |
| 4 | Jefferson County | 9 | 15% | 48 |
| 5 | Lewis and Clark County | 5 | 8% | 73 |
| 6 | Pondera County | 5 | 8% | 14 |
| 7 | Toole County | 3 | 5% | 5 |
| 8 | Madison County | 2 | 3% | 29 |
| 9 | Teton County | 1 | 2% | 11 |
Hour of day
Share of fatal crashes on Interstate 15 beginning in each hour, 2015–2024; tick marks the Montana share for all roads.
Where along the route
| Mile marker range | Fatal crashes | Share |
|---|---|---|
| Mile 125–130 | 5 | 8% |
| Mile 120–125 | 4 | 7% |
| Mile 280–285 | 3 | 5% |
| Mile 340–345 | 3 | 5% |
| Mile 60–65 | 2 | 3% |
| Mile 90–95 | 2 | 3% |
Five-mile bins by FARS milepoint, the six with the most fatal crashes; 98.4% of crashes on the route have a milepoint. Milepoints are as recorded by the state and can restart at county or district lines.
Other routes in Montana
- Interstate 90 193
- US Route 93 116
- US Route 2 103
- US Route 87 64
- US Route 212 55
- State Route 200 45
- US Route 12 43
- US Route 89 35
- Interstate 94 31
- US Route 191 24
- State Route MT 23
All routes and counties in Montana
Questions and answers
How many fatal crashes have there been on Interstate 15 in Montana?
61 fatal crashes with 65 deaths over 2015–2024, per NHTSA's FARS. The route is the trafficway recorded for the crash; the same numbered route in another state has its own page.
Which counties along Interstate 15 had the most fatal crashes?
Cascade County (15), Beaverhead County (10), Silver Bow County (10), Jefferson County (9) and Lewis and Clark County (5).
What share of crashes on Interstate 15 involved alcohol or speeding?
24.6% had a driver reported as drinking and 29.5% a speeding-related driver, against 43.9% and 35.8% for all fatal crashes in Montana.
When do fatal crashes happen on Interstate 15?
36.1% of the crashes were between 6pm and 6am. The hour chart on this page shows the full distribution.
Provenance
Source: NHTSA Fatality Analysis Reporting System, annual national CSV files 2000–2024 (accident, vehicle and person tables), public domain. Route pages are built for signed Interstate, US and state routes with at least 20 fatal crashes in 2015–2024. Data through 31 Dec 2024; generated 30 Sep 2026. See methodology and corrections.