Montana IFTA Calculator

Montana is one of the largest states by area but one of the least densely populated, creating vast stretches of isolated highway where fuel stops can be 50 or more miles apart. I-90 runs east-west across the southern portion of the state from the Idaho border at Lookout Pass through Missoula, Butte, Bozeman, and Billings to the Wyoming border. I-15 runs north-south from Idaho through Butte, Helena, and Great Falls to the Canada border at Sweet Grass. These two interstates form an L-shape that handles most of Montana's commercial freight. Coal from the Powder River Basin, oil from the Bakken formation that extends into eastern Montana, and agricultural output from the wheat-growing Hi-Line region are the primary freight generators.

Montana's IFTA rate of $0.2775 per gallon is moderate. Idaho at $0.320 to the west is higher. Wyoming at $0.240 to the south is slightly cheaper. North Dakota at $0.230 to the east is also cheaper. South Dakota at $0.280 is roughly comparable. Plan fuel stops in Wyoming before heading north into Montana on I-15 if your route allows.

Standard weight limits are 80,000 lbs. Montana has extensive roads that are effectively gravel or improved gravel — Bakken oil field service trucks routinely operate on these, and weight limits on county roads in eastern Montana are aggressively enforced by county sheriffs. Oversize permits for oil field equipment are a major permit category in eastern Montana. The Going-to-the-Sun Road through Glacier National Park is completely off-limits to commercial vehicles over a certain length and weight.

Winter in Montana is severe on every major route. I-90 over Lookout Pass, I-90 through the Bozeman Pass, and I-15 through Roger's Pass all see frequent closures and chain requirements from October through April. Fuel availability in the Hi-Line region and eastern Montana is limited — do not let your tank drop below half in these areas. For IFTA compliance, Montana miles driven on county roads for oil field service work must still be captured in your IFTA mileage logs even if no fuel is purchased in those remote areas.