Montana DUI Guide

Montana DUI Stops, Roadblocks, and the Open Container Law

Three questions that come before any DUI charge: can an officer pull me over, can police set up a checkpoint, and can anyone in the car have an open drink.

Written by

Misty Gaubatz, Partner, A&M Law

Licensed Montana attorney and co-founder of A&M Law. Over two decades in the practice of law focusing on family law, criminal defense, and DUI defense, with federal and state court experience and a Certificate in Mediation.

Montana Bar #122346+ years as an attorney, with over two decades working in the lawReviewed by Ashley HurlbertLast reviewed: October 1, 2026

Key Takeaways: Montana Stops and Open Container Law

An officer needs particularized suspicion of an offense to stop a vehicle (MCA § 46-5-401), and the stop may last no longer than necessary (MCA § 46-5-403).
Montana law authorizes temporary roadblocks for three listed purposes. The statute does not use the words sobriety checkpoint (MCA § 46-5-502).
A crash-area roadblock needs a written plan, a set pattern for which vehicles are stopped, and 48 hours' notice to the media (MCA § 46-5-510).
It is unlawful to knowingly possess an open alcoholic beverage container in the passenger area of a motor vehicle on a highway. That includes passengers (MCA § 61-8-1026).
The maximum fine is $100, and the violation may not be recorded on a driving record or used by an insurer.
Public intoxication is not a crime in Montana (MCA § 53-24-107).

Every DUI case starts with a police contact, and the lawfulness of that contact is the first thing a defense examines. This page covers the three rules people ask about most: the standard for a traffic stop, what Montana law says about roadblocks, and the open container law. It is part of our Montana DUI Guide.

When an Officer Can Stop You

The standard is particularized suspicion. A peace officer may stop any person or vehicle "observed in circumstances that create a particularized suspicion that the person or occupant of the vehicle has committed, is committing, or is about to commit an offense" (MCA § 46-5-401(1)). A traffic violation the officer saw, such as speeding, a lane violation, or a broken taillight, generally meets it. A hunch does not.

For a stop under the traffic code, the officer must tell you the reason as promptly as possible, unless there is an emergency or a safety concern.
The officer may ask for your driver's license, registration, and proof of insurance (MCA § 46-5-401(2)).
The stop "may not last longer than is necessary to effectuate the purpose of the stop" (MCA § 46-5-403). Turning a traffic stop into a DUI investigation requires something more, such as the odor of alcohol or what the officer observes.

If a stop lacked particularized suspicion, or was extended without grounds, a defendant can move to suppress what followed, and suppressed evidence is not admissible at trial (MCA § 46-13-302).

Roadblocks and Checkpoints

Montana's roadblock statute was rewritten, and much of what is online describes the old version. The current law, MCA § 46-5-502, authorizes a law enforcement agency to set up a temporary roadblock on a highway for three purposes:

to apprehend persons known to be wanted for a violation of law;
to respond to an active emergency;
to respond to or mitigate conditions in areas where a significant number of known causal factors of motor vehicle accidents involving fatalities, injuries, or other serious legal violations are known to have occurred.

During a temporary roadblock, officers may require verification of a valid driver's license, registration, and insurance. For the third kind of roadblock, an officer may not issue a ticket for a secondary offense, and the agency must have a written plan (MCA § 46-5-510) that:

prevents the arbitrary selection of vehicles by setting the pattern of vehicles to be stopped;
is approved in advance by supervisory officers;
keeps the roadblock minimally intrusive and does not leave officers unconstrained discretion;
includes a public service announcement, with major media outlets in the area notified at least 48 hours before.

The statute does not use the phrase "sobriety checkpoint," and it neither names nor forbids one. We did not find a Montana Supreme Court decision ruling squarely on a sobriety checkpoint. If you were stopped at a roadblock, the questions are which purpose it was set up under and whether the plan, the pattern, and the notice requirements were actually followed.

The Open Container Law

A person commits the offense by knowingly possessing an open alcoholic beverage container within the passenger area of a motor vehicle on a highway (MCA § 61-8-1026(1)). Each part of that sentence is defined (MCA § 61-8-1001):

Open container: a bottle, can, jar, or other receptacle that contains any amount of an alcoholic beverage and is open, has a broken seal, or has had some contents removed. A re-corked wine bottle counts.
Alcoholic beverage: a drink that contains 0.5% or more alcohol by volume.
Passenger area: the area designed to seat the driver and passengers, and any area readily accessible to them while seated, including an unlocked glove compartment.
Highway: includes the shoulders.

Exceptions

The law does not apply to an open container that is (MCA § 61-8-1026(2)):

in a locked glove compartment or storage compartment;
in a trunk, luggage compartment or rack, truck bed, or cargo compartment;
behind the last upright seat of a vehicle with no trunk;
in a closed container in an area not normally occupied by the driver or a passenger, in a vehicle with no trunk;
in the immediate possession of a passenger in a bus, taxi, or limousine used to transport people for compensation with a hired driver;
in the immediate possession of a passenger in the living quarters of a camper, travel trailer, or motor home.

Penalty

The fine may not exceed $100. The statute provides that a violation may not be recorded or charged against a driver's record and that an insurer may not hold it against the insured or increase premiums because of it (MCA § 61-8-1026(3)). A parallel statute addresses marijuana in a vehicle (MCA § 61-8-1027).

The practical risk of an open container is not the $100. It is that an open container in view gives an officer a reason to look further, and it becomes evidence in a DUI investigation.

Public Intoxication

Being intoxicated in public is not a crime in Montana. A person who appears intoxicated in public "does not commit a criminal offense solely by reason of being in an intoxicated condition," though an officer may detain the person for their own protection (MCA § 53-24-107). Cities and counties may not adopt ordinances that make intoxication itself an offense (MCA § 53-24-106). That protection does not extend to driving, or to other conduct such as disorderly behavior.

For what happens after a stop turns into an investigation, see field sobriety tests and test refusal and implied consent.

This page explains Montana law in general as of the 2025 Montana Code Annotated. It is not legal advice about your specific case.

Montana DUI Guide DUI Defense Prescription & Drug DUI The DUI Court Process How Long a DUI Stays on Your Record What a DUI Costs

FAQ

Montana DUI Stops, Roadblocks, and the Open Container Law FAQ

Are DUI checkpoints legal in Montana?

Montana's statute authorizes temporary roadblocks for specific purposes, including responding to conditions in areas where a significant number of serious crashes or violations have occurred, and it sets conditions for them (MCA §§ 46-5-502, 46-5-510). It does not mention sobriety checkpoints by name, and we did not find a Montana Supreme Court decision squarely ruling on one. So the accurate answer is that roadblocks are permitted under stated conditions, and whether a particular one was lawful depends on whether those conditions were met.

Can police pull me over for no reason in Montana?

No. An officer may stop a vehicle that is observed in circumstances that create a particularized suspicion that an occupant has committed, is committing, or is about to commit an offense (MCA § 46-5-401). For a traffic stop, the officer must tell you the reason as promptly as possible unless there is an emergency or a safety concern. If the stop was not lawful, the evidence that came from it can be challenged.

Can a passenger drink alcohol in a car in Montana?

Generally no. The open container law applies to any person who knowingly possesses an open alcoholic beverage container in the passenger area of a motor vehicle on a highway. The passenger exception is limited to a bus, taxi, or limousine with a hired driver, and the living quarters of a camper, travel trailer, or motor home (MCA § 61-8-1026(2)).

What is the penalty for an open container in Montana?

A fine of not more than $100. The statute says the violation may not be recorded or charged against a driver's record, and an insurance company may not hold it against the insured or raise premiums because of it (MCA § 61-8-1026(3)).

Where can I legally carry an opened bottle in my vehicle?

In a locked glove compartment or storage compartment, in the trunk or luggage compartment, in a truck bed or cargo compartment, or behind the last upright seat of a vehicle that has no trunk (MCA § 61-8-1026(2)).

Is public intoxication illegal in Montana?

No. A person who appears intoxicated in public does not commit a criminal offense solely by being intoxicated, though an officer may detain the person for their own protection (MCA § 53-24-107). Local governments may not make intoxication itself an offense (MCA § 53-24-106). Driving is different, and so is other conduct while intoxicated.

Think the Stop Was Not Lawful?

Whether the officer had grounds to stop you is often the first issue in a DUI case. Call 406-830-3060 for a confidential consultation.

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