Dave Johnson, 57, reportedly waited about two hours to be discovered after sustaining the injury on Thursday morning.
The Rapid City Journal reported that Johnson ventured off the park's 1.5-mile Notch Trail, slipped, and fell through a crack in a rock face. Johnson's cell phone did not have any reception from the place where he got stuck, the Journal's Ruth Moon reported. Two hikers from Belgium spotted him at about 10:30 a.m. on Thursday and called 9-1-1.
Johnson was said to be in fair condition at Rapid City Regional Hospital on Thursday night.
The 244,000 acre park attracted more than 870,000 visitors in 2011.