Haula signed with the Minnesota Wild and is expected to finish the season with Houston of the AHL. He was a seventh-round pick by the Wild in 2009.
The Philadelphia Flyers signed Alt, who was drafted by Carolina in the second round in 2010 and whose rights went to Philadelphia in a trade earlier this season.
Forwards Nick Bjugstad (Florida) and Zach Budish (Nashville) and defenseman Nate Schmidt (Washington) also gave up their senior seasons to sign pro deals.
Haula averaged more than a point per game for the Gophers, with 124 points in 114 career games. He led the team this season with 51 points and was second with 16 goals.
Alt was plus-19 this season for Minnesota, which led the WCHA in defense. He had seven assists in 39 games.