DUI / DWI Defense, Missoula

Being arrested for driving under the influence in Missoula is frightening, and the consequences reach far beyond a single night. A DUI conviction in Montana can mean jail time, steep fines, a suspended license, higher insurance costs, and a criminal record that follows you for years. But an arrest is not a conviction, and you have rights at every step.

How Montana Defines DUI

Montana law makes it illegal to operate a vehicle while under the influence of alcohol or drugs, or with a blood alcohol concentration (BAC) at or above the legal limit. Montana recodified its impaired-driving statutes in 2021 (Title 61, Chapter 8, Part 10 of the Montana Code Annotated). You can be charged in two ways: a “per se”DUI based purely on your BAC, or a DUI based on actual impairment, meaning the State doesn't always need a breath test to bring a charge.

• 0.08%, standard limit for drivers 21 and over
• 0.04%, commercial driver's license (CDL) holders
• 0.02%, drivers under 21 (Montana's zero-tolerance approach)

The THC / Marijuana DUI Standard

Marijuana is legal in Montana, but driving while impaired by it is not, and THC DUI charges are a fast-growing area of enforcement. Montana addresses cannabis-impaired driving in two ways. First, there is a per se limit of 5 nanograms per milliliter (ng/mL) of delta-9-THC in whole blood: at or above that level you can be charged with DUI without separate proof of impairment. Second, you can be charged based on actual impairment at any THC level if cannabis affected your ability to drive safely. THC is measured by a blood test rather than a breath test, and because THC can linger in the blood well after any impairment fades, these cases are often genuinely contestable.

A&M Law has successfully resolved a number of these cases. For a full explanation of the science, the testing, and the defenses, see our THC / Marijuana DUI defense page.

Montana DUI Penalties at a Glance

Penalties increase sharply with each offense and with aggravating factors such as a very high BAC, a refusal, or driving on a suspended license. The table below is a general guide, your exact exposure depends on the specific charge and your history.

Your License Is at Risk Immediately

Under Montana's implied-consent law, driving on a public road counts as agreeing to chemical testing if lawfully arrested for DUI. Refusing a breath or blood test triggers an automatic license suspension, separate from the criminal case and effective even if you're never convicted. There is only a short window to petition for a hearing to challenge that suspension, so the clock starts the day you're arrested.

How A&M Law Defends DUI Cases

Misty Gaubatz brings a perspective most defense attorneys can't: she has worked in prosecution, so she knows how the State builds a DUI case, and she is certified in NHTSA Standardized Field Sobriety Tests, the same certification the arresting officer holds. That means she can scrutinize exactly how your stop, your tests, and your breath sample were handled. We commonly examine:

• Whether the officer had a lawful reason for the traffic stop
• Whether field sobriety tests were administered to NHTSA standards
• Whether the breath-testing instrument was properly calibrated and maintained
• How any blood sample was drawn, stored, and tested
• Whether your constitutional rights were respected throughout

We prepare every DUI case as if it will go to trial. That preparation is exactly what creates leverage, whether your case is resolved through a motion to suppress, a negotiated reduction, or a verdict.