My best friend and I are planning a trip from Boise, ID to Kentwood, MI and are planning on driving mostly along I90, but what are some good places to see and stop?
We are already planning on seeing Yellowstone, Crazy Horse, and Mt Rushmore, but what are other places that we wouldnt think of? We want to see all the "local" stuff that tour books wouldn't suggest.
What things have you all done that you loved?
PS. We are 21yr old college students, so free and cheap places are best ;)