It is illegal in Montana to drive or be in actual physical control of a vehicle on a public road while you are under the influence of drugs and/or alcohol.
Under .04 – It may be inferred that the driver is not under the influence.
.04 - .08 – Whether the driver is under the influence may be determined by considering the alcohol level and relevant testimony from the arresting officer.
.08 or greater – It may be inferred that the driver is under the influence of alcohol, however this inference is rebuttable.
The limit for drivers of commercial vehicles is a BAC of .04 or greater.
The first conviction carries a mandatory minimum of 24 hours in jail and a minimum fine of $300. The maximum penalty is 6 months and $1,000.
Jail time increases to 48 hours – 12 months and the fine becomes $600 - $1,000.
The second conviction will result in a fine of $600 - $1,000 and imprisonment for 7 days – 6 months.
The fine increases to $1,200 - $2,000 and jail time increases to 14 days – 12 months.
The third conviction will result in a fine of $1,000 - $5,000 and imprisonment for 30 days – 12 months.
The fine increases to $2,000 - $10,000 and jail time increases to 60 days – 12 months.
The fourth and subsequent convictions are felonies. These will result in a jail term of 13 months. If the offender completes a residential alcohol treatment program in jail, the remainder of his term may be served on probation. There is also a fine of $1,000 - $10,000.
If the driver is under the age of 21, it is illegal to have a BAC of .02 or greater.
$100 - $500 Fine.
$200 - $500 Fine and up to 10 days in Jail.
$300 - $500 Fine and up to 60 days in Jail.
In Montana, the second and subsequent DUI conviction will result in the forfeiture of any and all vehicles owned by the person at the time of the offense. To prevent forfeiture, you may request that the court place an ignition interlock device on the vehicle. This device will prevent the car from being driven while the driver has a BAC of .02 or greater.
In addition to all other penalties, the court will require that anyone convicted of a DWI, regardless of how many he has, must complete a chemical dependency assessment and education course. On the second and third convictions, the court will require the defendant to complete a residential alcohol treatment program.
It is illegal to possess an open container of alcohol in the passenger area of a vehicle. A conviction results in a fine of up to $100.