While playing senior hockey in Eveleth, Minnesota, Williamson was noticed by the legendary coach John Mariucci and was recruited to play for the University of Minnesota in 1955. His hockey skills eventually culminated with West All-American honors in 1959. Following a short semi-pro career in Ontario, Williamson took on the role as player/coach and general manager of the St. Paul Steers in the USHL from 1962-1966. That team eventually became the U.S. National Team launching Williamson into an illustrious international coaching career beginning with the World Tournament in Vienna, Austria, in 1967 and continuing through the World Junior Tournament in Winnipeg, Canada in 1974. In 1970, he coached the U.S. Team to the gold medal in the World Championships. And in the 1972 Olympic at Sapporo,