You will really enjoy the trip. Barb and I have camped in most off these ares. Be prepared for very very hot temperatures which means drinking heaps of water on the tour. Death Valley can get over 54c, with this kind of temperature you will soon dehydrate and heat stroke can come on very fast. Even the camping grounds are closed in summer due to the heat. If you get up into the Rocky's you can get up to some 12,000 feet on sealed Roads. In May there should still be snow up there with the mornings being some what cold in May. To catch all the wild life you have to be up in the mountains early before all the waves of hog riders come through and send all the wild life away. We have traveled some 20,000 miles over the last 8 years in the west side of the states mostly camping and driving a soft top car.