A rock climber died on Sunday evening after he fell from Devils Tower National Monument, a hulking rock formation in northeast Wyoming, park officials said.

The climber, Stewart Phillip Porter, 21, of Eau Claire, Wis., fell shortly before 8 p.m. while rappelling the second pitch of El Cracko Diablo, one of the hundreds of parallel cracks that divide the roughly 870-foot tower into large columns, the National Park Service said in a news release Monday. It did not say how far Mr. Porter fell, and calls and emails to the service on Tuesday were not immediately returned.