Wappingers Falls, Ny to Yellowstone and Glacier

For a trip that included Yellowstone and Glacier I would make a loop, with the direction of travel depending on the time of year. For a Spring trip, I would take a southern route west and hit Yellowstone first. Then hit Glacier after the Going to the Sun road opens in late June/early July and then head back east on a northern route. For a Fall trip, take the opposite direction around the loop to see Glacier before the Going to the Sun road closes.