West Montana suggestions

As for the Glacier Park area and RV parks, I would suggest several - Mountain Meadows, the West Glacier KOA or St. Mary's, as we've stayed at both. Be sure to do the Going to the Sun Road, the drive to Polebridge, and with your passports or driving passes, be sure to drive to Waterton Lakes in Canada taking the scenic Chief Joseph scenic byway. Visit the Prince Albert hotel and historic site and have lunch in town. Then, go out to the lake and hike the trail around it. Take your binoculars as you may see bears across the lake. We returned to our site at the St. Mary's KOA via Hwy 5 to Cardston. Another note on campgrounds within the park - Glacier has a great site on the status of their campgrounds and some are open after Labor Day.