Born in White Bear Lake, Minnesota, Brooks played hockey at the University of Minnesota and was a member of the 1964 and 1968 United States Olympic teams. Later, he coached the University of Minnesota's hockey team to three NCAA championships (1974, 1976 and 1978). He coached St. Cloud State University in the mid 1980s.
He was coach of the United States hockey team at the 1980 Winter Olympics that won the gold medal. The team, made up of college age players, defeated Finland in the final match of the round robin group, after beating the Soviet Union in the previous game.
The Soviet Union, which had won four consecutive Olympic titles from 1964 to 1976, was considered the best team at these Olympics, while the US reaching the final round robin pool was already considered a surprise. In the match against the USSR, the American team came back from behind three times until a late goal by Mike Eruzione in the third period sealed the match. Another hero of the team was goalie Jim Craig, with 39 saves. The victory later became known as "The Miracle on Ice".
Brooks died in a one-car accident in Forest Lake, Minnesota.