Montana Noise Laws (2026): Disorderly Conduct, Decibels, Nuisance

Montana state law sets decibel limits for vehicles and makes loud noise a crime when it is disorderly conduct, but quiet hours and noise limits for homes come from city ordinances. Under MCA 45-8-101(1)(b), a person who "knowingly disturbs the peace by" "making loud or unusual noises" commits disorderly conduct, punishable by a fine of up to $100, up to 10 days in the county jail, or both. A 2025 law also rewrote Montana's private nuisance statutes, which a neighbor can use to sue over noise, for claims arising on or after October 1, 2025. To compare other states, see our guide to noise ordinance laws by state.

Information last verified on 2026-10-10. This article has not been reviewed by a licensed lawyer.

Jurisdiction scope: This article covers Montana state law: disorderly conduct and criminal public nuisance (MCA 45-8-101, 45-8-111); vehicle noise rules for exhaust, motorcycles, mufflers, horns and engine compression brakes (61-9-435, 61-9-418, 61-9-403, 61-9-401, 61-9-321) with their penalties (61-9-511, 61-9-521) and statewide uniformity (61-9-103); city and town powers over noise and nuisances (7-32-4302, 7-5-4104); motorboat and snowmobile noise (23-2-523, 23-2-526, 23-2-634, 23-2-642); funeral picketing (45-8-116); city and town ordinance penalties (7-5-4207, 7-5-109, 7-1-4150); the 2025 private and public nuisance statutes (27-30-101, 27-30-106, 27-30-303, 27-30-305; Ch. 531, L. 2025); shooting range protections (76-9-102, 76-9-104); the home digital asset mining carve-out (76-2-1003); the tenant duty not to disturb neighbors and the landlord's notice (70-24-321, 70-24-422); fireworks sale dates and state park discharge (50-37-106, 50-37-103); and the public use site rules (ARM 12.12.104, 12.12.140). It does not cover the text of any city or county noise ordinance, county or self-government charter powers, lease terms, aircraft or workplace noise, or the law of other states. Statute text is the 2025 Montana Code Annotated as the Montana Legislature publishes it.

Montana noise laws at a glance

Disorderly conduct: Montana's main noise offense

Section 45-8-101(1) states that "A person commits the offense of disorderly conduct if the person knowingly disturbs the peace by" any of a list of acts, including "(b) making loud or unusual noises." The person must act knowingly, and the noise must disturb the peace.

The penalty is modest: "a person convicted of the offense of disorderly conduct shall be fined an amount not to exceed $100 or be imprisoned in the county jail for a term not to exceed 10 days, or both" (45-8-101(2)). A higher penalty in subsection (3), a fine of up to $1,000, up to 1 year in the county jail, or both, applies only to a violation of subsection (1)(i), not to loud noises under (1)(b).

Criminal public nuisance

Montana's criminal public nuisance statute reaches a broader problem than one neighbor's party. A "public nuisance" includes "a condition that endangers safety or health, is offensive to the senses, or obstructs the free use of property so as to interfere with the comfortable enjoyment of life or property by an entire community or neighborhood or by any considerable number of persons" (45-8-111(1)(a)). A person convicted of maintaining a public nuisance "shall be fined an amount not to exceed $500. Each day of the conduct constitutes a separate offense" (45-8-111(6)). "Noises resulting from the shooting activities at a shooting range during established hours of operation are not considered a public nuisance" (45-8-111(5)). An agricultural or farming operation, place, establishment or facility does not become a public nuisance through its normal operation because of changed residential or commercial conditions around it, if it has been in operation longer than the complaining resident has been in possession (45-8-111(4)).

Funeral picketing

Montana's funeral picketing offense is defined largely by noise. "Picketing" includes "the making of any noise or diversion that can reasonably be expected to disturb a funeral by" acts that include "engaging, with or without the use of a sound amplification device, in loud oration, speech, singing, chanting, whistling, or yelling that is not part of the funeral services" (45-8-116(5)(c)). The offense is knowingly picketing "within 1,500 feet of any property boundary entrance to or exit from a funeral site" from 1 hour before the scheduled start of the services until 1 hour after they end (45-8-116(1)). The penalty is a fine of $250 to $1,000, up to 12 months in the county jail, or both (45-8-116(2)). A district court may enjoin the conduct and may award damages, including punitive damages, and attorney fees in a civil action (45-8-116(3), (4)).

Vehicle noise: Montana's statewide decibel limits

Montana is one of the states whose vehicle noise rules use decibel figures.

Cars and trucks. "Except as provided in subsection (2), a person may not operate a motor vehicle with an exhaust system that emits a noise in excess of 95 decibels, as measured by the society of automotive engineers' standard j1169 (May 1998)" (61-9-435(1)). The section "does not apply to a motorcycle or quadricycle that is subject to 61-9-418" (61-9-435(2)). In 2025 the Legislature passed Ch. 378, L. 2025 (SB 264), "AN ACT ELIMINATING A DEFENSE TO THE EXHAUST NOISE LIMITATION STATUTE." It struck the sentence that said a person "may not be convicted if the person had reasonable grounds to believe that the vehicle was not operated in violation of the standard."

Motorcycles and quadricycles. On streets and highways they must have noise suppression devices, "including an exhaust muffler, in good working order and in constant operation," and must meet these limits on the A scale, "measured at 50 feet from the closest point to the motorcycle or quadricycle" (61-9-418(1)):

Off highways on public lands, a motorcycle or quadricycle may be operated only if its noise emissions do not exceed 96 dB(A) under SAE standard J-1287, except at special events permitted on closed courses by a state entity or local government (61-9-418(2)).

Mufflers and horns. "Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise and annoying smoke, and no person shall use a muffler cutout, bypass, or similar device upon a motor vehicle on a highway" (61-9-403(1)). "A horn or other warning device may not emit an unreasonably loud or harsh sound or a whistle," and a driver may not use the horn on a highway except to give a warning "when reasonably necessary to ensure safe operation" (61-9-401(1)).

Engine brakes. A commercial motor vehicle with an engine compression brake "must be equipped with a muffler in good working condition to prevent excessive noise" (61-9-321(1)). An operator whose engine brake has "a factory-installed muffler or an equivalent after-market muffler may not be prohibited from using the engine compression brake device" (61-9-321(2)). A violation of 61-9-321 is a misdemeanor with a fine of up to $500 (61-9-521).

Penalties and local rules for vehicle noise

"It is a misdemeanor for any person to violate any of the provisions of this chapter unless the violation is declared to be a felony" (61-9-511(1)). For a provision "for which another penalty is not provided," the fine is $10 to $100 for a first conviction, $25 to $200 for a second conviction within 1 year, and $50 to $500 for a third or later conviction within 1 year after the first (61-9-511(2)). Those are the statutory ranges, not a scheduled amount.

The vehicle equipment chapter applies uniformly statewide, and "a local authority may not enact or enforce any ordinance, rule, or regulation in conflict with the provisions of this chapter unless expressly authorized in this chapter," though local authorities "may adopt additional traffic regulations that are not in conflict" (61-9-103(1)).

Boats and snowmobiles

Motorboats and personal watercraft. For the purposes of the disorderly conduct and public nuisance statutes, operating a motorboat or personal watercraft "that emits noise in excess of 86 dbA when measured at a distance of 50 feet or emits exhaust noise in excess of 90 dbA measured 1 meter from the muffler at idle speed" under SAE J2005 "is presumed to be a public nuisance and constitute disorderly conduct, except when otherwise lawfully operated under a motorboat racing permit issued by a political subdivision of the state" (23-2-526(3)). A stricter limit applies on Flathead Lake, Echo Lake and Swan Lake: a motorboat or personal watercraft may not be operated in proximity to the shoreline if the noise emitted is greater than 75 dbA measured at the shoreline under SAE J1970 (23-2-523(9)).

Snowmobiles. Each snowmobile must have noise-suppression devices, "including an exhaust muffler in good working order and in constant operation," and may not be modified to increase its noise above the level it emitted as originally built (23-2-634(1)). A snowmobile made after June 30, 1972 but before June 30, 1975 must be kept at or under 82 dbA measured at 50 feet, and one made after June 30, 1975 at or under 78 dbA at 50 feet (23-2-634(2), (3)). A violation carries a civil penalty of $15 to $500 for each violation, or $50 to $1,000 if the violation is willful (23-2-642(2)).

Quiet hours at state parks and fishing access sites

The Fish and Wildlife Commission's 2023 public use site rule, ARM 12.12.104, prohibits at public use sites operating speakers, radios, televisions or other sound-emitting electronic equipment at a volume that projects sound in a manner that disturbs others (ARM 12.12.104(1)(e)), and:

"(f) operating generators where prohibited or during public use site quiet hours between 10:00 pm and 7:00 am."

"In addition to any other penalty posted by the department, individuals violating this rule may be expelled immediately from the public use site" (ARM 12.12.104(2)). Under the companion penalty rule, a violator may be expelled from a public use site "for up to 48 hours," and "Failure to comply with the expulsion may constitute criminal trespass" (ARM 12.12.140(2)).

Quiet hours at home are set by your city or town

Apart from the rules above, none of the state statutes on this page sets quiet hours, construction hours or decibel limits for homes. Those rules, where they exist, are in local ordinances.

Montana gives cities and towns a direct grant over noise: "Within the city or town and within 3 miles of the limits thereof, the city or town council has power to prevent and punish intoxication (subject to the limits established in 53-24-106), fights, riots, loud noises, disorderly conduct, obscenity, and acts or conduct calculated to disturb the public peace or which are offensive to public morals" (7-32-4302).

A city or town's nuisance power changed on January 1, 2026, when Ch. 522, L. 2025 (HB 742) took effect. Section 7-5-4104(1)(a) now gives the council power to "define, control, and abate all conditions: (i) that endanger health or safety; (ii) that are offensive to the senses; or (iii) that obstruct the free use of property that interferes with the comfortable enjoyment of life or property by an entire community or neighborhood or by any considerable number of persons." The amendment struck the earlier clause that let a council "impose fines upon persons guilty of creating, continuing, or suffering a nuisance."

A city or town may punish a violation of its ordinances with a fine of up to $500 and imprisonment of up to 6 months for any one offense (7-5-4207(1)); the same ceiling applies to any local government's ordinances (7-5-109(1)). A municipality may instead provide by ordinance that a violation is a municipal infraction, a civil offense with a civil penalty of up to $300, or up to $500 for each repeat violation (7-1-4150(1), (2)). Your city or town's code states which route and amount it uses.

One state law expressly preserves local noise ordinances: local rules on digital asset mining may not prevent "home digital asset mining at a private residence, except as related to existing noise ordinances" (76-2-1003(1)(c)).

To find your rule, look up your city or town's code of ordinances on its website or ask the city clerk, and check with the county if you live outside city limits.

Dealing with a loud neighbor in Montana

• A disturbance happening now: call your local police or sheriff's non-emergency line; knowingly disturbing the peace by loud or unusual noises is disorderly conduct (45-8-101(1)(b)).
• A recurring problem: ask your city or town code enforcement office or clerk which noise ordinance applies and how complaints are filed.
• Renters: a tenant must "conduct oneself and require other persons on the premises with the tenant's consent to conduct themselves in a manner, that will not disturb the tenant's neighbors' peaceful enjoyment of the premises" (70-24-321(1)(f)). If a tenant breaks this duty, the landlord may give a written notice describing the problem and ending the lease in not less than 14 days; the lease does not end if the breach is remediable by repairs, the payment of damages, or written approval of the landlord and the tenant remedies it before that date (70-24-422(1)(a), (d)). If substantially the same problem recurs within 6 months, the landlord may end the lease on at least 5 days' written notice (70-24-422(1)(e)). See Montana landlord-tenant laws for how leases and notices work.
• Fireworks: state law allows retail sales of permissible fireworks only from June 24 through July 5 and from December 29 through December 31 (50-37-106), and makes it unlawful to discharge fireworks within a state forest, state park or state recreation area (50-37-103(6)(a)). See Montana fireworks laws for more.

Suing for private nuisance under the 2025 law

Ch. 531, L. 2025 (HB 791) rewrote Montana's nuisance statutes. It "applies to a cause of action that accrues on or after October 1, 2025. A cause of action that accrued prior to October 1, 2025, is governed by the law applicable immediately before October 1, 2025" (Ch. 531, L. 2025, section 14(1)).

Under the new law, "A private nuisance is a condition arising out of the use of real property that: (a) is injurious to health or safety, indecent or offensive to the senses of an individual on an adjacent or neighboring property," or (b) obstructs the free use of an adjacent or neighboring property so as to interfere with the comfortable enjoyment of life or property (27-30-106(1)).

• Who may sue: "a person whose property is injuriously affected or whose personal enjoyment of property is lessened by the private nuisance" (27-30-303).
• Remedies: "(1) injunctive relief to enjoin an activity proximately causing the private nuisance; (2) monetary and nonmonetary resources, if quantifiable," to abate it, established by clear and convincing evidence; and "(3) damages proximately caused by the private nuisance" (27-30-305).

Three things may not be the basis of a private nuisance claim (27-30-106(2), (3)):

1. An action or condition "that is authorized, approved, licensed, or mandated by statute, ordinance, regulation, permit, license, order, rule, or other similar measure" issued or approved by a government entity.
2. "Noises resulting from the shooting activities on a shooting range during established hours of operation."
3. The normal operation of "An agricultural or farming operation, a place, an establishment, or a facility," when the complaint arises from changed residential or commercial conditions around it, if it "has been in operation longer than the complaining resident has been in possession or commercial establishment has been in operation." This covers businesses and other facilities, not only farms.

How the first exclusion applies to a particular permitted activity is a question to raise with a Montana lawyer.

A civil public nuisance claim has similar limits: an action or condition that is lawful, or that is authorized, approved, licensed or mandated by a government measure, and "noises resulting from the shooting activities at a shooting range during established hours of operation" may not be its basis (27-30-101(2)(a) to (c)), and the same rule protects places and facilities that were operating first (27-30-101(3)).

Shooting ranges

Beyond the nuisance exclusions above, "Standards adopted by a state agency or unit of local government to limit levels of noise that may occur in the outdoor atmosphere may not apply to shooting ranges" (76-9-102(1)). A planning or zoning measure may not "prevent the operation of an existing shooting range as a nonconforming use" or "prohibit the establishment of new shooting ranges, but it may regulate the construction of shooting ranges to specified zones" (76-9-104).

Related pages

• Noise ordinance laws by state
• Montana landlord-tenant laws
• Montana fireworks laws
• Idaho noise ordinance laws
• Wyoming noise ordinance laws

This article provides general legal information about Montana law, not legal advice. For advice about a specific situation, contact a lawyer licensed in Montana or your city, town or county government.

Last updated: 2026-10-10.

Frequently Asked Questions

What are the noise laws in Montana?

Knowingly disturbing the peace by making loud or unusual noises is disorderly conduct under MCA 45-8-101(1)(b). Vehicle exhaust may not exceed 95 decibels (61-9-435), and motorcycles have decibel limits by model year (61-9-418). Quiet hours and limits for homes come from city ordinances.

What are the quiet hours in Montana?

Public use sites such as state parks and fishing access sites have generator quiet hours from 10:00 p.m. to 7:00 a.m. (ARM 12.12.104). None of the state statutes on this page sets quiet hours for homes, so check your city or county code.

Is a loud neighbor disorderly conduct in Montana?

It can be if the neighbor knowingly disturbs the peace by making loud or unusual noises (45-8-101(1)(b)). The penalty is a fine of up to $100, up to 10 days in the county jail, or both (45-8-101(2)).

Can I sue my neighbor for noise in Montana?

For a cause of action that accrues on or after October 1, 2025, a person whose property is injuriously affected or whose personal enjoyment of property is lessened by a private nuisance may sue (27-30-303). Remedies are an injunction, quantifiable abatement resources proven by clear and convincing evidence, and damages (27-30-305). A claim that accrued before October 1, 2025 is governed by the earlier nuisance law, which also let a person whose property was injuriously affected or whose personal enjoyment was lessened sue for an injunction, abatement and damages.

How loud can a car exhaust be in Montana?

A motor vehicle exhaust system may not emit a noise above 95 decibels as measured by SAE standard J1169 (61-9-435). Motorcycles and quadricycles follow the separate limits in 61-9-418.

What is the fine for a loud exhaust or muffler in Montana?

A violation of the vehicle equipment chapter is a misdemeanor. Where no other penalty is provided, the fine is $10 to $100 for a first conviction, $25 to $200 for a second within 1 year, and $50 to $500 for a third or later within 1 year (61-9-511).

Can a shooting range be sued for noise in Montana?

For a claim that accrues on or after October 1, 2025, noise from shooting activities at a range during established hours of operation is not a private nuisance (27-30-106(2)(b)). It is not a criminal public nuisance (45-8-111(5)), and state or local outdoor noise standards may not apply to shooting ranges (76-9-102(1)).