Walter Eagle Tail of Custer began choking during the contest and died at a hospital after attempts to revive him at the scene were unsuccessful.
"There was someone doing CPR when we arrived," Custer County Sheriff Rick Wheeler told the Rapid City Journal. "Basically, he probably just suffocated. It got lodged in his throat and they couldn't get it out."
Eagle Tail was one of six contestants taking part in the competitive-eating event.
"It all happened within minutes," Wheeler said. "I think everybody was pretty well shocked about it."
A pie eating contest that was planned for the next day was canceled after Eagle Tail's death.
"We are at a loss for words," said Custer Area Chamber of Commerce Executive Director Dave Ressler. "We are mourning for Walter and his family right now."