30 day trip out West - Dare we without reservations?

Make a list of the possible campsites in each area you plan to visit. Start with the one you wanted and then go to pre planned alternate sites if full. During the summer, it should be fairly easy to get a spot Sunday through Thursday. On weekends, forget the popular destination places. Go to the popular spots during the week and the not popular spots for your weekends to minimize your chances of full campgrounds. Even stay at an RV Park if nothing else is available. Have a good trip.