You're looking at Rainbow Bridge in Utah. It is one of the largest natural bridge spans in the world at 234 feet (31 m), at the top it is 42 feet (13 m) thick, 33 feet (10 m) wide and has a height of 290 feet (88 m). It is considered as a sacred site by many Native tribes.
Before the drought when Lake Powell was nearly full, one could take a 50 mile boat ride north from Wahweep in Arizona and nearly get under Rainbow Bridge in the boat, as in this shot. Since the drought began, the lake level has continually dropped so much that it is about a two mile hike from the closest waters edge where you can dock a boat. It is no longer possible to get a reflection of the bridge in the water.