- 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