A remnant of the old 'Plank Road' in far-southern California...
A wooden road that crossed the Imperial Sand Dunes from 1914-1927. http://www.blm.gov/ca/st/en/fo/elcentro/arch_cult/plankrd.html
...Just 1/3 mile from the US-Mexico border fence!
Painted Rock Petroglyphs, Arizona
https://en.wikipedia.org/wiki/Painted_Rock_Petroglyph_Site
Painted Rock Petroglyphs, Arizona
https://en.wikipedia.org/wiki/Painted_Rock_Petroglyph_Site
Titan II Missile Museum, south of Tucson
https://en.wikipedia.org/wiki/Titan_Missile_Museum
Titan II Missile Museum, south of Tucson
https://en.wikipedia.org/wiki/Titan_Missile_Museum
Mission San Xavier del Bac, near Tucson
https://en.wikipedia.org/wiki/Mission_San_Xavier_del_Bac
Mission San Xavier del Bac, near Tucson
https://en.wikipedia.org/wiki/Mission_San_Xavier_del_Bac
Diamondback Pedestrian/Bike Bridge, Tucson
http://www.atlasobscura.com/places/diamondback-bridge
Kitt Peak National Observatory, southwest of Tucson
Kitt Peak National Observatory, southwest of Tucson
Saguaro National Park, near Tucson
Saguaro National Park, near Tucson
'Spaceport America', New Mexico
https://en.wikipedia.org/wiki/Spaceport_America
'Very Large Array' Radio Telescope, New Mexico
https://en.wikipedia.org/wiki/Karl_G._Jansky_Very_Large_Array