At Natural Bridge State Monument the Boulder River disappears underground, creating a natural bridge, then reappears as roaring falls in the Boulder River canyon. Hiking trails and interpretive signs explain how this geologic wonder occurred. The Main Boulder Ranger Station, a few miles past the bridge, is one of the oldest in the United States and is now an interpretive center.
Hwy. 298, 27 mi south of Big Timber, Big Timber, Montana, 59052, United States