I agree! When a kid, I took a three week trip from western NY state to “out west”. We made a big loop, up over the great lakes in Canada, then down through Michigan, etc. Seen some amazing things, Yellowstone, the Badlands, the four corners of the U.S., etc. All on state roads and camping the whole time!
 

I’ve never been to the Grand Canyon, but I did visit Mount Rushmore with my family as a teenager. This is a must-see that every American should visit at least once in their life time. Another impressive thing to see is Devil’s Tower in Wyoming ( remember the ending of Close Encounters of the Third Kind? ) We visited both of these on the way home from Yellowstone National Park, which is one of the most spectacular and unforgettable must-sees of all. Anyone who’s going there should plan on at least four or five days to see and experience everything. And people heading to Mount Rushmore shouldn’t miss the Badlands, not too far east of there. The terrain is so bizarre that you’ll think that you just landed on another planet.