According to an article in the Missoulian, dated September 28, 2015, drivers headed east from Idaho on I-90 will be restricted to 75 mph for the first 34 miles, from Lookout Pass to just east of St. Regis. After St. Regis, there'll be an 80 mph limit for the next 60 miles past Superior, Alberton and Frenchtown. The 20-mile zone around Missoula starts a couple of miles west of the Wye, where it drops to 75. That decreases to 65 mph within the Missoula urban area, then it becomes 75 again near the eastbound East Missoula on-ramp. The 80 mph stretch resumes roughly seven miles later at Turah and remains in place to Butte, where the speed limit remains at 65 mph.