Montana Engine & Jake Brake Rules

Montana has no statewide engine-brake ban. State law requires a working muffler with no cutout (MCA 61-9-403) and caps exhaust noise (MCA 61-9-435). The bans that get you ticketed are local ordinances on posted signs, seen around Whitefish and Columbia Falls near Glacier, along US-93 through Kalispell, and in towns like Bozeman and Livingston. A muffler answers a noise charge, not a posted ban. Keep compression braking on grades where nothing is posted.

Ban scopeLocal / posted

Muffler lawYes (the legal hook)

Where postedPosted zones sit near Glacier and the resort corridor: Whitefish and Columbia Falls, along US-93 through Kalispell, and towns like Bozeman, Livingston, and Red Lodge

FineLocal noise-ordinance citation set by the town or county, commonly about $50-$500

A detail here is flagged medium confidence — confirm with the state DMV or the local ordinance before you rely on it.

01 The rule

How Montana handles engine braking

02 On the road

What to watch for

Ban scope: Local / posted
Where posted & enforced: Posted zones sit near Glacier and the resort corridor: Whitefish and Columbia Falls, along US-93 through Kalispell, and towns like Bozeman, Livingston, and Red Lodge. Enforcement concentrates in those communities; wide rural stretches largely ignore the signs.
Muffler / noise law: Yes, the real legal hook
Fine: Local noise-ordinance citation set by the town or county, commonly about $50-$500.

Montana Engine Brake FAQ

Are engine brakes banned in Montana?

Montana has no statewide ban. The restriction is local and posted on "NO ENGINE BRAKE" signs. Montana has no statewide engine-brake ban.

Where are the "NO ENGINE BRAKE" signs in Montana?

Posted zones sit near Glacier and the resort corridor: Whitefish and Columbia Falls, along US-93 through Kalispell, and towns like Bozeman, Livingston, and Red Lodge. Enforcement concentrates in those communities; wide rural stretches largely ignore the signs.

What is the fine for using an engine brake where it is banned in Montana?

Local noise-ordinance citation set by the town or county, commonly about $50-$500.

Reference information for planning, not legal advice. Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it. Last reviewed July 2026. Source: https://codes.findlaw.com/mt/title-61-motor-vehicles/mt-code-ann-sect-61-9-403/. See our Terms & Disclaimer.

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Montana Engine & Jake Brake Rules

How Montana handles engine braking

What to watch for

Montana Engine Brake FAQ

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