Montana Boating Information
Registration Questions:(406) 444-3933
Boating Registration Website:
State Tax Department Website:
Registration Grace Period (Days):90 days
Boat Sales & Use Tax Rate:0%
Credit For Tax Paid In Another State:No
State Decal Required For Documented Vessel:Yes
Boat Titles Issued:Yes
Notes:Local Sales and Use Tax also apply. Titles issued for outboard motors.
Boating Law Administrator(406) 444-0136
Maximum Speed Limit:Posted Speed Limit
Maximum Dimensions For Trailer:53'L x 8'W x 14'H
Maximum Overall Length with Vehicle & Trailer:65'
Minimum Weight Requiring Separate Trailer Brakes:3000 lbs.
Trailer Equipment Requirements:
Safety Chains:Yes
Brake Lights:Yes
Clearance Lights:Yes
License Light:Yes
Turn Signals:Yes
Breakaway Brakes:Yes (Over 3000 lbs.)
Two Trailers:No Commercial Only
Tire Restrictions:
Insurance:Not required specifically for the trailer, may fall under the vehicle insurance.
Wide Trailer Permit Office:(406) 444-7262
For specific questions about boating issues or BoatUS Government Affairs, please e-mail the department at