Montana - 45-8-316. Carrying concealed weapons. (1) Every person who carries or bears concealed upon his person a dirk, dagger... sword cane... knife having a blade 4 inches long or longer, razor not including a safety razor, or other deadly weapon shall be punished by a fine... or imprisonment... - 45-8-317. Exceptions [officials; permit holders] (9) a person who is outside the official boundaries of a city or town or the confines of a logging, lumbering, mining, or railroad camp or who is lawfully engaged in hunting, fishing, trapping, camping, hiking, backpacking, farming, ranching, or other outdoor activity in which weapons are often carried for recreation or protection; or (10) the carrying of arms on one's own premises... - 45-8-331. Switchblade knives. (1) Every person who carries or bears upon his person, who carries or bears within or on any motor vehicle or other means of conveyance owned or operated by him, or who owns or possesses, uses, stores, gives away, sells, or offers for sale a switchblade knife shall be punished by a fine not exceeding $500 or by imprisonment in the county jail for a period not exceeding 6 months or by both... (2) A bona fide collector whose collection is registered with the sheriff of the county in which said collection is located is hereby exempted from the provisions of this section. (3) For the purpose of this section a switchblade knife is defined as any knife which has a blade 1 1/2 inches long or longer which opens automatically by hand pressure applied to a button, spring, or other device in the handle of the knife. http://www.knife-expert.com