In 2011, he became the first coach in Bulldog history to lead them to a national title, in a 3–2 overtime game against the University of Michigan at the Xcel Energy Center in Saint Paul, Minnesota.

In the 2018 NCAAs, he led the Bulldogs to a second national title, over Notre Dame 2–1, also played at the Xcel Energy Center.

Sandelin grew up in Hibbing, Minnesota, where he went on to be drafted in the second round by the Montreal Canadiens (40th overall) and play collegiate hockey for the North Dakota Fighting Sioux.

Sandelin's NHL career totaled seven seasons with the Canadiens (1986–88), Philadelphia Flyers (1990–91), and his home state team, the Minnesota North Stars (1991–92).

He has also produced three Hobey Baker winners in Junior Lessard in 2004, Jack Connolly in 2012, and Scott Perunovich in 2020, along with 15 future NHL hockey players and 17 All WCHA selections.

The Bulldog's earned a trip to the Frozen Four by beating Bowling Green (2-1 OT) and Quinnipiac (3-1).

The Bulldog's finished the season by beating UMass (3-0) earning Sandelin's third coaching championship.

Sandelin led the 2019-20 Bulldogs to 2nd place in the NCHC regular season, but due to the COVID-19 pandemic the conference and NCAA tournaments were cancelled.