The 22-year-old forward was originally selected by Chicago in the first round, 24th overall, of the 2010 NHL Entry Draft.
More recently, Hayes was playing for Boston College, registering 27 goals and 38 assists in 40 games.
Hayes became a viable target for teams outside of the Windy City when the Blackhawks failed to sign him with the team by last weekend's deadline.
Hayes had some options with some familiar faces. His brother Jimmy is with the Florida Panthers and his Boston College linemates Bill Arnold and Johnny Gaudreau are in Calgary.
The Dorchester, Massachusetts native has also represented Team USA on several occasions. Most recently, Hayes tallied two points (one goal, one assist) in eight games at the 2014 IIHF World Championship in Minsk, Belarus.