Free: Contests & Raffles.
Uncle Tom’s Trail in the Grand Canyon and Dragons Breath Cave as mentioned.
also, don't know which entrances you plan on taking, but the NE entrance and beartooth pass to Cooke City, MT is stunning!
It will be early September and we will likely use the NW or West entrance. Doesn't mean we can't take a drive out to the NE entrance of its that spectacular to see. Thanks for the input so far, I will add them all to my list and see how much we can check off of it along the way. We are really looking forward to the trip.