The boating regulations contain information on the following topics:
Water Body Restrictions
Rules of the Road
Children 12 years old or younger may not operate a motorboat or a personal watercraft powered by a motor rated at more than 10 horsepower unless accompanied by someone 18 years of age or older.
Youths 13 and 14 years of age may not operate those vessels without possessing a valid Montana motorboat operator's safety certificate or evidence of completing an approved boating safety course, or unless accompanied by someone 18 years of age or older.
Lakes 35 Acres or Less (PDF)
All watercraft operating on public lakes and reservoirs in the western fishing district that are 35 acres or less of surface water are limited to no-wake speed. These lakes have been determined 35 acres or less by means of the 1:100,000-scale hydrography layer within the department’s geographic information system (GIS).
Lakes Greater than 35 Acres (PDF)
All watercraft operating on public lakes and reservoirs greater than 35 surface acres within the western fishing district are limited to no-wake speed from the shoreline to 200 feet from the shoreline.
The exceptions include:
PWC which must maintain a minimum operating speed to remain upright and maneuver in the water may travel at that minimum operating speed following the most direct route through the nowake zone to and from shore.
Motorized watercraft towing a skier from or to a dock or the shore, except that watercraft must travel the most direct route through the no-wake zone.
The following closures and public use restrictions are in effect for reasons of public health, safety or protection of property. Only authorized exceptions such as search and rescue, scientific purposes or special events with the director’s prior written approval are exempt. Some waterways have multiple restrictions that apply, so be sure to check all of the following sections for the body of water you plan to use. Other dams not listed here may also be posted for restricted access.
RESTRICTIONS AT DAMS
The following dams are closed to all boating, sailing, floating and swimming or closed to all public access as marked by boat restraining systems or signs.
The following lakes located with the Thompson Chain of Lakes in Lincoln county:
Crystal Lake - Horseshoe Lake
Loon Lake - Lower Thompson Lake
McGregor Lake - Middle Thompson Lake
Upper lobe of Upper Thompson Lake
Echo Lake in Flathead County is limited to a 200 feet from shoreline no wake speed except for the following areas:
(a) the upper three islands in the southwest corner of section 5, approximately 1/4 mile southeast of the entrance of Blackies Bay;
(b) the narrow corridor that serves as the entrance and exit to Blackies Bay located in the northwest corner of Echo Lake; and (c) the narrow corridor that serves as the entrance and exit to Causeway Bay located in the northeast corner of Echo Lake.
Lake Five in Flathead County
Written permission from Montana Fish, Wildlife & Parks is necessary to conduct a boating race, regatta or other marine event on Montana's waters. Letters of application must be sent at least 30 days prior to the scheduled event. Mail to: Montana Fish, Wildlife & Parks, Boating Law Enforcement, P.O. Box 200701, Helena, MT 59620-0701.
Boating accident reports are required by law and provide valuable information for use in the prevention of future boating accidents. An accident must be reported immediately to the local sheriffs office or game warden if it caused:
The operator of a boat involved in a collision, accident, or other casualty must:
Boating accident report forms are available from the county sheriff's office, game wardens, or any Montana Fish, Wildlife & Parks office.
Sailboats 12 feet long and longer and all motorboats and personal watercraft must be registered and numbered. Non-motorized sailboats less than 12 feet long and manually propelled boats, regardless of length, are exempt from registration and taxation. Also exempt are a vessel’s lifeboat and government-owned boats.
Boat owners must obtain a certificate of ownership (title) and certificate of number (registration) and pay all fees to the County Treasurer in the county where the owner resides. The certificate of number must be carried on board the boat and be available for inspection whenever the boat is in operation. Registration fees are based on the length and age of the vessel.
Boats that are properly registered in another state or country may operate in Montana for up to 90 consecutive days.
Homemade boats or boats manufactured before 1972 that require registration must first have a hull identification number. Generally the 12-digit hull identification (HIN) number is on the exterior of the vessel’s transom in the upper-right corner.
A boat owner may obtain a HIN number from any Fish, Wildlife & Parks regional or area office. The application fee is $5. The boat owner is responsible for permanently affixing the HIN number on the boat and having the boat inspected by a peace officer.
Under MCA 61-3-321, all motorboats, personal watercraft, motorized pontoons and sailboats 12 in length and longer must be permanently registered. This is done through the County Treasurer's Office.
View the quick reference on Understanding Montana's Required Boat Decals
The boat number must:
The boat owner will receive one permanent registration decal as proof of payment of fees in lieu of tax. The permanent decal must be displayed on the left (port) bow behind the boat’s number. The permanent decal is valid until the current owner sells the watercraft.
All motorboats, sailboats, and personal watercraft that are numbered must display two validation decals, one on each side of the boat’s bow behind the boat’s number.
Validation decals may be obtained, free of charge, at any Montana Fish, Wildlife & Parks regional/area offices or online:
Orange validation decals will expire February 28, 2026. Boat owners should remove each red decal or cover it with the new orange decal.