Some Montana attractions near the I90 corridor: Bighorn Battlefield near Crow Agency (7th Cavalry RV Park nearby gets good reviews). Museum of the Rockies at Bozeman includes lots of paleontology, pioneers and a planetarium. Camping about 30-40 miles west at Missouri Headwaters State Park or Lewis and Clark Caverns State Park give you an opportunity to explore Virginia City, Helena or Butte. The World Museum of Mining is a fascinating stop in Butte. The Territorial Prison, a car museum, a toy museum and Grant - Kohrs Ranch NHS are all at Deerlodge. Unless one is seriously into back country hiking, Glacier is the last place I would go in Montana. There are so many more less crowded and scenic places all over the state. While it is beautiful it is being loved to death like so many other of our parks.