petrified forest national park, agate bridge
We entered the park at the north entrance, and after visiting the Painted Desert Visitor Center, we began the 28-mile scenic drive through the park.
Agate Bridge is a 110-foot long petrified log, each end of which is embedded in sandstone, forming a natural bridge over the gully below it. In 1917 workers added the concrete span below the petrified log to help support it. If Agate Bridge were to be discovered today, it would be left in its natural state, due to current National Park Service philosophy.