[twindman]

Agree with most posts. When we retired, our goal was to see all National Parks. Finished last summer. Some advice to all. If you plan on visiting Utah or Arizona (my home) in June, pretty much everywhere that has red rock :-) the temps will be greater than 110 for sure. That is pretty much all of Utah. Four corners area. So walking around taking pictures is HOT.
Next, my favorite place is the Big Horn mountains in Wyoming. Just pretty there. From Cody, head east on Highway 14 to hit I25 (?) for the road to Custer area. Unless you are adventurous, stay away from 14A. My wife won't let me take it after the first time. The Mountainous Driving book calls it the "Oh My God" hill. 8 miles of 8% and 10 miles of 10% grades.
Oh, if you are in the mountains of Wy,Mt, or Co in June, you could be in snow so dress warmly.