Montana

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.