Montana Title 61. Motor Vehicles § 61-8-371. Operation of motor vehicle or off-highway vehicle below high-water mark on certain state or federal lands prohibited--exceptions

(1) Except as provided in 77-1-111(3), 77-1-806(4), and subsections (2) and (3) of this section, a person may not operate a motor vehicle or an off-highway vehicle below the ordinary high-water mark, as defined in 23-2-301, of class I or class II waters, as defined in 23-2-301, that occurs on state or federal lands or below the ordinary high-water mark of class I waters flowing through private lands, within that portion of the streambed that is covered with water.

(2) A motor vehicle or an off-highway vehicle may be operated below the ordinary high-water mark on state or federal lands on an established road or trail that enters or crosses a stream, but the stream crossing must be by the shortest practical or designated route to the road or trail on the opposite bank.

(3) The prohibition in subsection (1) does not apply to:

(4) The state may authorize the use of a motor vehicle or off-highway vehicle on state property below the ordinary high-water mark only when the state has determined that the use will have a minimal impact on the streambed and on the fish and wildlife ecology of the stream or river. Federal land management agencies are requested to apply the same criteria when authorizing use of federal land.