I plan on spending about 10 days with family in yellowstone/grand Tetons/ glacier park. In late August. I know parks will be crowded but only time we can go. I'd like to break up trip into maybe 3 three day stops. We like day hiking more adventurous stuff (not resort type people). I know nothing about this area at all. Any one have any ideas on things we should definitely include in our plans. Will likely fly north then rent a car, probably look for VBRO homes to stay at. Thanks!