I. The trails within the system shall be held, developed and administered under this chapter primarily as recreational trails for hiking, nature walks, bird watching, horseback riding, bicycling, ski touring, snowshoeing, snowmobiling, mushing, and off highway recreational vehicles and the natural scenic beauty thereof and the wildlife corridors and habitat strongholds as defined in N.H. Rev. Stat. § 207:1 therein shall be preserved insofar as is practical; provided, however, that the commissioner may permit uses of trails and land acquired hereunder, by the owner of adjoining land or others, in such a manner and at such seasons as will not substantially interfere with the primary use of the trails. Use of motorized devices by mushers shall be limited to trails designated as appropriate for motorized use.
II. Nothing in this section shall be construed to limit the right of the public to pass over existing public roads which may be or become part of the trail system, deny any owner access to his land or prevent the department from performing such work as is necessary for the purpose of forest fire prevention and control, insect pest and disease control and the removal of damage caused by any natural acts.
III. The commissioner is authorized to zone and restrict use of any section of the trails after consultation with the director of the division of parks and recreation, the director of the division of forests and lands, the executive director of the department of fish and game, and such other local and state officials as he shall determine, who may be able to assist him in determining appropriate public uses for such trails. A restriction on the use of any type of a mechanized means of transportation on portions of the trail shall be imposed by the commissioner where, in his opinion, it would be most disruptive for the other stated principal trail uses.