I just returned from a road trip which included Glacier NP. I rode a loop from the Apgar Campground-Camas Entrance-Columbia Falls-West Glacier-Apgar. The section of Highway 2 from Columbia Falls to West Glacier is to be avoided at all costs. As a previous poster indicated the road is narrow with marginal shoulders between Columbia Falls and Hungry Horse. An alternative route is head north out of Columbia Falls and take Blankenship Road east and ride good gravel to West Glacier. The NPS has a nice large format map of the park that shows the route. You can call 406-888-7800 and ask for a copy of the 18'x18" map labeled "Glacier". The GTS Highway is undergoing major road work and I opted to not ride it. During the summer you need to be over the pass by 1100am. No restrictions after Labor Day.