Reviewed and updated October 9, 2026 by the SearchSystems.net editorial team. The arrest counts are the ones each agency reported to the FBI, as the FBI held them on October 8, 2026. The jail figures are from the Vera Institute of Justice's Incarceration Trends data. Every office link was opened and checked against the office's own site between September 24, 2026 and September 30, 2026.
Petroleum County, Montana, has 525 residents (2024 Census Bureau estimate). A DUI arrest in Petroleum County starts two cases, a criminal case in a Justice or Municipal Court and a license case before the Motor Vehicle Division, and leaves three records. This guide follows the arrest from the roadside to the court file and the driving record.
This guide covers the law, the arrest, booking, the court case, the license case, the records and common questions.
Related guides: Petroleum County public records, Petroleum County arrest records, Petroleum County warrants, Petroleum County inmate search, Petroleum County criminal records, Montana arrest records and Montana inmate search.
The DUI Law in Montana
Drunk driving is charged as DUI in Montana, at a blood alcohol level of 0.08 or more.
Driving in Montana is consent to a breath or blood test when an officer has cause to suspect DUI; the license case that follows a refusal or a failed test is run by the Motor Vehicle Division, separately from the criminal case.
Who Makes DUI Arrests in Petroleum County
The Petroleum County Sheriff's Office makes the DUI arrests in Petroleum County.
The Petroleum County Sheriff's Office reported 1 arrests to the FBI for 2025, all offenses together; the FBI's count for Petroleum County does not break DUI out.
Booking After a DUI Arrest in Petroleum County
A driver arrested for DUI and kept in custody goes to the county jail, whichever agency made the arrest. The jail, run by the Petroleum County Sheriff's Office, held about 1 people on an average day in 2019 by the Vera Institute of Justice's count and has a jail page SearchSystems verified at petroleumcountymt.org/departments/sheriffs-department, phone (406) 429-6551. The Petroleum County inmate search guide covers the jail in full.
The Court Case
A DUI charge from Petroleum County is heard in a Justice or Municipal Court; the County Attorney or, in a municipal court, the city's own prosecutor brings it.
The court records page SearchSystems verified for the county is at courts.mt.gov/Courts/portals.
Montana has no single public index of every trial court case; each court's records are looked up through that court.
The License Case
The court case is only half the record. The Motor Vehicle Division runs a separate administrative case over the license, which can suspend it before the criminal case is decided, and the Montana Motor Vehicle Division keeps the driving record the conviction goes on.
The Records a DUI Leaves
- The arrest report: from the agency that made the arrest, under the Montana Public Records Act.
- The court file: from a Justice or Municipal Court, kept by the Clerk of District Court.
- The driving record: from the Montana Motor Vehicle Division.
More on each: Petroleum County arrest records, Petroleum County police reports and Petroleum County court records.
Frequently Asked Questions
What is the DUI limit in Montana?
0.08 percent blood alcohol.
Where is a DUI case from Petroleum County heard?
In a Justice or Municipal Court. The court records page SearchSystems verified for the county is at courts.mt.gov/Courts/portals.
Where is a person arrested for DUI in Petroleum County held?
At the county jail, run by the Petroleum County Sheriff's Office, if kept in custody.
Who handles the license after a DUI arrest in Montana?
The Motor Vehicle Division, in an administrative case separate from the court case.
Is this the official Petroleum County website?
No. SearchSystems.net is an independent public records guide, online since 1997. It links to the official county, court and state offices described above and does not hold records, charge for them or take requests.