Heard, a 20-year-old center, was taken in the second round (No. 41). Last season with the Plymouth Whalers in the Ontario Hockey League, he had 57 points (29 goals, 28 assists) in 57 games.
"We are pleased to have Mitchell under contract," Avalanche general manager Greg Sherman said in a statement. "He is coming off a strong season in the OHL and we are excited to see him at training camp."
The 6-foot-1, 190-pound forward is a native of Bowmanville, Ontario.