jeff14 - I think you will be better off to visit Utah parks first and then work your way up to Glacier NP; as several have pointed out the Going-to-the-Sun-Road isn't open many years until early July. By doing Utah first you also may avoid the hot weather down there which can get kinda warm (but you're from St Louis so maybe it doesn't matter, and Utah hot isn't near as humid as what you are used to) Have a good trip, include Many Glacier in your visit (have passports, and other stuff ready for the border crossing).