Impaired-Driving Crashes in Missoula County, 2016 to 2025

What this means for Missoula County drivers

• "Suspected" is the officer's call at the scene. The crash report records whether law enforcement suspected alcohol or drug use; it is not a blood or breath test result, a charge or a conviction. If you were arrested after a crash, our Missoula DUI defense page explains what happens next.
• Impaired driving shows up most in the worst crashes. Crashes with a driver suspected of impairment killed or seriously injured someone 10.2% of the time, against 3.1% for other crashes, about 3 times as often.
• Nights and weekends. 40% of the Missoula County crashes with suspected impairment (and a recorded time) happened between 9 p.m. and 3 a.m., and 36% happened on a Saturday or Sunday. On Sundays, 12.5% of all crashes involved a driver suspected of impairment; on Tuesdays, 4.7%.
• Most drivers involved are Montanans. 90% of drivers suspected of impairment in Missoula County crashes held a Montana license; 185 held a license from another state or Canadian province, most often Washington. Visitors facing a charge can read about out-of-state DUI cases in Montana.
• Alcohol is the main factor recorded. Officers suspected alcohol in 1,795 of the 1,940 crashes and drugs in 1,199, usually together with alcohol: drugs without alcohol were suspected in 145. Our page on THC and marijuana DUI covers drug cases.
• If an impaired driver hurt you, our guide for people hurt by a drunk driver in Montana explains the first steps.

Crashes with a driver suspected of impairment, by county, 2016 to 2025

Missoula, Ravalli and Lake counties, the six other Montana counties with the most crashes, and the state.

Suspected impairment = law enforcement recorded suspected alcohol or drug use by at least one driver. Ten years combined. Butte-Silver Bow is listed in MDT's data as Silver Bow County.

Missoula County: crashes with suspected impairment by year

Yearly fatal counts are small and swing from year to year. The CSV download splits each year into crashes with alcohol suspected and crashes with drugs suspected (one crash can have both).

Missoula County: crashes with suspected impairment by day of the week, 2016 to 2025

Missoula County: crashes with suspected impairment by month, 2016 to 2025

December and January have the most crashes overall, so the share with suspected impairment is lower in winter even though the counts are similar to other months.

Drivers suspected of impairment, by license state, 2016 to 2025

Counts drivers, not crashes: a crash with two drivers suspected counts twice. Shares are of drivers with a license state recorded. Not recorded includes blank fields and codes that do not name a state, province or country.

How we did this

We used the Montana Department of Transportation's crash database extract for 2016 to 2025 (crash and person tables, updated October 8, 2026, downloaded November 12, 2026). A crash counts as involving suspected impairment when at least one person recorded as a driver has "Law Enforcement Suspected Alcohol Use" or "Law Enforcement Suspected Drug Use" marked Yes. Fatal crashes and serious-injury crashes use the crash table's severity field; deaths count people whose injury severity is recorded as fatal.

Times of day use the crash time field. 278 Missoula County crashes are recorded at exactly 00:00, far more than any neighboring minute, so we treat that value as time not recorded and leave those crashes out of the time-of-day figures. Day of week and month use the crash date.

A second, separate script re-reads the original Excel files with a different reader and recomputes the headline figures. It also checks Missoula County's fatal crashes and deaths for each year from 2016 to 2024 against NHTSA's Fatality Analysis Reporting System (FARS; the 2024 file is preliminary), and the county's crash totals against MDT's public crash map service.

Limits

• "Suspected" is the officer's judgment recorded on the crash report. It is not a test result, a charge or a conviction, and officers may not always mark it, especially when a driver leaves the scene or dies.
• MDT describes the file as a one-time extraction: crash locations have not been reviewed, and details may change as MDT staff analyze the data further. Recent years can still change.
• Fatal crash counts are small for one county (8 to 21 a year in Missoula County), so a single year's share moves a lot. The ten-year totals are steadier.
• NHTSA's FARS uses its own police-reported alcohol measure for fatal crashes, so its count of drinking drivers will not match MDT's suspected-impairment count exactly.
• Crash data is collected for safety analysis. Under federal law (23 U.S.C. 407), this crash data can't be discovered or admitted as evidence in court, or considered in a lawsuit for damages; it describes patterns only.
• The figures cover crashes reported to law enforcement. Crashes nobody reported are not in the data.