Montana Studded Tire Law
Metal studs are legal October 1 through May 31 (MCA 61-9-406) — one of the longest windows in the country; school buses get August 15 to June 15, and retractable studs run any month. Montana sets no GVW cap, so a loaded truck can run studs in season, capped at 1/16-inch projection. When Montana posts a traction or chain order, chain up. Studs don't count.
Running studs in Montana
Metal studs are legal October 1 through May 31 (MCA 61-9-406) — one of the longest windows in the country; school buses get August 15 to June 15, and retractable studs run any month. Montana sets no GVW cap, so a loaded truck can run studs in season, capped at 1/16-inch projection. When Montana posts a traction or chain order, chain up. Studs don't count.
The window and winter-tire rules
- Season: October 1 to May 31 (MCA 61-9-406). School buses: August 15 to June 15. Pneumatic tires with retractable studs may be used any month.
- No statewide M+S or 3PMSF mandate. MDT posts chain / traction-device requirements when conditions warrant; fixed metal studs do not satisfy a posted chain order, so see the Montana chain-law page and chain up. Stud/embedded-material projection capped at 1/16 inch. Truck weight cap: none, studs legal for trucks in season.
Montana Studded Tire FAQ
Are studded tires legal in Montana?
When can you use studded tires in Montana?
What is the fine for illegal studded tires in Montana?
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 Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it.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://mca.legmt.gov/bills/mca/title_0610/chapter_0090/part_0040/section_0060/0610-0090-0040-0060.html. See our Terms & Disclaimer.
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