The scenic route in
Petrified Forest National Park, Arizona, crosses hwy 40, which was once a part of historic Route 66. A little memorial in a parking lot comemorates America's most famous highway.
Most things in this Park are 225 mil. years old. This one isn't that old yet and it is also not yet petrified. However, it must have been here long enough for souvenier hunters to strip it it off any possible mean of identification.