Montana open carry laws let any adult who is legally eligible to possess a firearm carry it openly in public, with no permit, license, training course, or background check required by the state.1Montana Department of Justice. Concealed Weapons Open carry has long been the default in Montana. The harder questions are who counts as eligible, where the right ends, and how federal rules layer on top of state law.
Who Can Open Carry
If state and federal law both allow you to possess a firearm, you can carry it openly in most public places in Montana. No paperwork, no fee.
Age is where state and federal law meet. Montana bars children under 14 from carrying a firearm in public unless a parent, guardian, or authorized adult is with them.2Montana State Legislature. Montana Code 45-8-344 – Use of Firearms by Children Under 14 Years of Age Prohibited – Exceptions Federal law generally bars anyone under 18 from possessing a handgun, so 18 is the practical minimum for openly carrying a pistol or revolver. Long guns can be carried at younger ages under state law with appropriate supervision. Federal law also sets 21 as the minimum age to buy a handgun from a licensed dealer, though private sales and gifts can put a handgun into the hands of an 18-year-old legally.
Who Is Prohibited from Carrying
Montana Prohibitions
Montana bars firearm possession by certain convicted felons: anyone whose felony carried a weapons enhancement at sentencing, anyone with an equivalent out-of-state felony, and anyone required to register as a sexual or violent offender. Unlawful possession under this statute is punishable by 2 to 10 years in prison.3Montana State Legislature. Montana Code 45-8-313 – Unlawful Possession of Firearm by Convicted Person
Carrying a concealed weapon while under the influence of an intoxicating substance is a separate crime, punishable by up to six months in jail, a fine up to $500, or both.4Montana State Legislature. Montana Code 45-8-327 – Carrying Concealed Weapon While Under Influence The statute names concealed carry specifically, but carrying openly while intoxicated invites other criminal liability. Alcohol, drugs, and firearms do not mix.
Federal Prohibitions
Federal law under 18 U.S.C. § 922(g) adds categories of prohibited persons that apply nationwide. You cannot possess a firearm or ammunition if you are an unlawful user of or addicted to any controlled substance, are subject to a domestic violence restraining order, or have been convicted of a misdemeanor crime of domestic violence.5Bureau of Alcohol, Tobacco, Firearms and Explosives. Identify Prohibited Persons The last category, known as the Lautenberg Amendment, catches people off guard: a misdemeanor conviction for something like simple assault against a spouse or family member triggers a lifetime federal firearms ban.6U.S. Marshals Service. Lautenberg Amendment
Other federal disqualifiers include any felony conviction, an active fugitive warrant, adjudication as mentally defective, dishonorable military discharge, and renunciation of U.S. citizenship. Violations carry up to 10 years in federal prison, and Montana’s permitless framework does not override them.
Where Open Carry Is Off-Limits
School Buildings
Firearms of any kind are prohibited inside school buildings owned or leased by a local school district and used for instruction or student activities. Law enforcement and sanctioned school programs are exempt; almost no one else is. A violation is punishable by a fine up to $500, up to six months in jail, or both.7Montana State Legislature. Montana Code 45-8-361 – Possession or Allowing Possession of Weapon in School Building – Exceptions – Penalties – Seizure and Forfeiture or Return Authorized – Definitions The statute says “school building,” not school grounds broadly, but federal Gun-Free School Zone rules may also apply near schools.
Government Buildings
Local governments can restrict both open and concealed carry inside publicly owned and occupied buildings under their jurisdiction.8Montana State Legislature. Montana Code 45-8-351 – Restriction on Local Government Regulation of Firearms A city hall or county courthouse can lawfully post no-firearms signage, and that signage binds open carriers. Look for postings before you walk in.
A separate statute makes it a crime to carry a concealed weapon without a permit in restricted areas of state or local government buildings, punishable by up to $500, up to six months in jail, or both.9Montana Code Annotated. Montana Code 45-8-328 – Carrying Concealed Weapon in Prohibited Place – Penalty Holders of a Montana concealed weapon permit or a recognized out-of-state permit are exempt.
Federal Facilities
Federal buildings are governed by federal law, and Montana’s permissive rules do not apply. Knowingly possessing a firearm in a federal facility can bring up to a year in prison; in a federal courthouse, up to two years.10Office of the Law Revision Counsel. 18 U.S. Code 930 – Possession of Firearms and Dangerous Weapons in Federal Facilities Post offices are covered too. No firearms, open or concealed, are allowed on USPS property.11United States Postal Service. Possession of Firearms and Other Dangerous Weapons on Postal Service Property
Airports
Firearms cannot go past TSA screening. You can transport an unloaded firearm in checked baggage if it is locked in a hard-sided container and declared to the airline at the ticket counter.12Transportation Security Administration. Transporting Firearms and Ammunition TSA treats a firearm as loaded if a live round is in the chamber or magazine, or if the firearm and ammunition are both accessible to the passenger. Airlines can add their own fees and restrictions.
Federal Lands
Much of Montana is federal land, and the rules shift with the managing agency.
- National parks and forests: federal law defers to state law for firearm possession, so open carry is generally lawful on trails and in campgrounds in places like Glacier and Yellowstone. Firearms are not allowed inside any federal building within the park, including visitor centers, ranger stations, gift shops, and fee booths. Discharging a firearm in a national park unit requires specific authorization.13Office of the Law Revision Counsel. 54 U.S. Code 104906
- Army Corps of Engineers lands: federal regulations prohibit loaded firearms on all Corps-managed property, including lakes and recreation areas. Exceptions cover law enforcement, authorized hunting programs, and permitted shooting ranges only. Montana law does not override this.14eCFR. 36 CFR 327.13 – Explosives, Firearms, Other Weapons and Fireworks
- BLM lands: the Bureau of Land Management generally allows firearm possession. Discharge is prohibited on developed recreation sites unless the area is designated for target shooting, and fire season closures can add restrictions. Check with the local BLM office before shooting.15Bureau of Land Management. Recreational Shooting
College and University Campuses
Campus carry sits in an unsettled place. House Bill 102 originally allowed open and concealed carry on Montana University System campuses with narrow exceptions, but the Montana Supreme Court struck down those campus provisions, holding that the legislature had encroached on the constitutionally independent Board of Regents. The university system retains authority to set its own firearms policies. Before carrying on any Montana college or university campus, check that specific institution’s current rules. They can and do differ from the rest of the state.
Carrying in a Vehicle
Carrying a firearm inside a vehicle is straightforward. A gun placed in a visible location, such as on the seat, on the dashboard, or in an exposed holster, is openly carried and needs no authorization. Since permitless concealed carry became law, a firearm in a console or glove box also does not create legal exposure for anyone otherwise eligible to possess it.1Montana Department of Justice. Concealed Weapons The moment you cross a state line, that state’s rules take over. Montana’s permitless framework ends at the border.
Private Property
Property owners and tenants can prohibit firearms on their premises, whether the location is a home, a business, or any other private property. The restriction is usually communicated by a posted sign or a direct verbal request. If you are asked to leave because of your firearm and refuse, you can be charged with criminal trespass to property, punishable by a fine up to $500, up to six months in jail, or both.16Montana State Legislature. Montana Code 45-6-203 – Criminal Trespass to Property The owner does not owe you an explanation. Permitless carry governs public spaces, not someone else’s private property.
Local Government Regulation
Montana’s preemption law bars cities, towns, and counties from passing their own firearms rules in most situations. Local governments cannot prohibit, license, tax, or regulate the purchase, possession, or open carrying of any firearm.8Montana State Legislature. Montana Code 45-8-351 – Restriction on Local Government Regulation of Firearms A city cannot, for example, require a local carry permit or ban open carry on public streets.
Two exceptions matter. Cities and towns can regulate the discharge of firearms within their limits, so you can carry but not shoot. And local governments retain the authority to restrict carry inside publicly owned and occupied buildings, which lets a county library or city community center lawfully post a no-firearms policy.
What House Bill 102 Actually Did
Open carry did not begin with HB 102. It was already lawful throughout most of Montana. What Governor Gianforte signed in 2021 was permitless concealed carry, extending that same standard to concealed firearms in the places where open carry was already permitted.17State of Montana Newsroom. Governor Gianforte Signs Constitutional Carry Bill Into Law Before the bill, carrying concealed without a permit in certain locations, particularly inside city limits, could bring criminal charges. HB 102 eliminated that patchwork.
A Montana concealed weapon permit is still worth considering if you travel, because reciprocity with other states runs through the permit, not through Montana’s permitless status. County sheriffs issue the permits, and the Montana Department of Justice maintains the list of states Montana recognizes.1Montana Department of Justice. Concealed Weapons