Because it sits so far north, sharing a border with Canada, and because it also sits in the middle of the Rockies, August is the perfect time to visit Glacier National Park. Early summer can still be cold, and can even get snow, but by August temperatures are usually in the 70s and the weather is perfect for hiking, horseback riding, kayaking, and even swimming in the many glacial lakes. Going-to-the-Sun Road, the scenic route through the park, is also more likely to be open later in the summer.
These campgrounds, both inside Glacier, and in the quaint towns nearby, offer accommodations and hookups for RVs.
Related: The Coolest Kayaking Trips to Take in Your RV