We are planning a trip to the southwest beginning about the last week of February. We hope to see Death Valley, Joshua Tree, Saguaro, Carlsbad Caverns, Guadalupe Mountains, and Big Ben National Parks...
If you enjoy visiting caverns, my favorite is Caverns of Señora in Texas. A great tour, and the most beautiful formations I've seen. Some photos from my 2012 trip.. There is an inexpensive water & electric campground at the cavern.