Montana Tire and Chain Laws

The Department of Transportation may determine at any time (year-round) that dangerous or unsafe conditions on a highway require tire chains in designated areas where tire chains may be required.

When the Department of Transportation determines tire chains or traction equipment are required, all vehicles towing a trailer (towing units) must apply chains to the driver wheels of one axle. AutoSock's are an approved alternative to tire chains. Designated chain-up and removal area signs are posted in areas where tire chains may be required. Ref: MCA 61-9-406

Studded winter tires are permitted in Montana from October 1 to May 31 of the following year, except that one of those tires may be used for a spare in case of tire failure. School buses equipped with such tires are permitted from August 15 to June 15 of the following year. Ref: MCA 61-9-406

Between October 1 and April 30 of the following year, towing units 26,001 GVW or greater must carry tire chains or an approved traction device when traveling in an area where tire chains may be required. Note: This does not apply to a vehicle with four-wheel drive. Ref: MCA 61-9-436

Current Signs in Use

Signs with flashing beacons affixed

road sign that reads: State law when flashing, chains required for towing units

Signs that flip open

road sign that reads: chains required for towing units

Locations Where Tire Chains May Be Required

Route Location Mountain Pass Name County
Interstate 15 I-15 MM148-143
Southbound only		 Elk Park Hill Jefferson
Interstate 15 I-15 MM168-175
Both directions		 Boulder Hill Jefferson
Interstate 90 I-90 MM4-0 (ID line)
Westbound only		 Lookout Pass Mineral
Interstate 90 I-90 MM228-241
Both directions		 Homestake Pass Silverbow-Jefferson
Interstate 90 I-90 MM256-262
Both directions		 Cardwell Hill Jefferson
Interstate 90 I-90 MM319-323
Both directions		 Bozeman Hill Gallatin-Park
Interstate 90 I-90 MM548-554 (WY line)
Eastbound only		 Aberdeen Hill Big Horn
US 2 US-2 MM7-4
Westbound only		 Yaak Hill Lincoln
US 2 US-2 MM179-199
Eastbound only		 Goatlick Hill-Marias Pass Flathead-Glacier
US 2 US-2 MM192-199
Eastbound only		 Marias Pass Flathead-Glacier
US 12 US-12 MM4-0 (ID line)
Westbound only		 Lolo Pass Missoula
US 12 US-12 MM12-30
Both directions		 Deep Creek Canyon Broadwater-Meagher
US 12 US-12 MM23-35
Both directions		 MacDonald Pass Powell-Lewis and Clark
US 20 US-20 MM2-0 (ID line)
Westbound only		 Targhee Pass Gallatin
US 87
MT 200		 US-87/MT-200 MM86-95
Both directions		 Lewistown Divide Fergus
US 89 US-89 MM25-33
Both directions		 Kings Hill Meagher-Cascade
US 87
US 89
MT 200		 US-87/US-89/MT-200 MM71-75
Northbound/Westbound only		 Belt Hill Cascade
US 93 US-93 MM8-0 (ID line)
Southbound only		 Lost Trail Pass Ravalli
US 93 US-93 MM4-7
Northbound only		 Evaro Hill Missoula
US 191 US-191 MM10-13
Both directions		 Fosters Hill Fergus
US 191 US-191 MM14-18
Southbound only		 Judith Gap Hill Wheatland
US 191 US-191 MM84-91
Both directions		 Missouri Breaks Fergus-Phillips
US 212 US-212 MM46-54
Both directions		 Lame Deer Divide Rosebud
US 212 US-212 MM80-83
Both directions		 Home Creek Divide Powder River
US 287 US-287 MM56-64
Both directions		 Norris Hill Madison
MT 43 MT-43 MM4-0
Southbound only		 Chief Joseph Pass Beaverhead-Ravalli
MT 200 MT-200 MM86-93
Both directions		 Rogers Pass Lewis and Clark
MT 287 MT-287 MM4-14
Both directions		 Virginia City Hill Madison
S 278 S-278 MM30-35
Both directions		 Big Hole Pass Beaverhead

Montana Codes Annotated

Motor Vehicles
Restrictions As To Tire Equipment
Violation of Tire Chain Or Traction Device Use
Certain Vehicles To Carry Tire Traction Devices During Winter Months