Gilbert Ray Campground in Tucson was our favorite stop. Operated by Pima County, the fabulous setting is atop a hill overlooking saguaro in every direction.
The museum advances a strongly ecological theme depicting riparian habitats, long gone, where lived river otters, beavers, herons, and fish. The finale was the frightening exhibit of reptiles and invertebrates including several species of rattlesnakes and a tarantula much bigger and hairier than your hand.
Finally, we got to empathize with vultures by wearing their wings: