 A native of Macomb, Illinois, where his father, Jack, was coach at Western Illinois University, Margenthaler earned All-State basketball honors as a senior at Macomb High School.After graduating from Indian Hills Community College in Iowa, he transferred to Southern Illinois University Edwardsville where his father was the new head coach.Margenthaler was a two-year starter for the SIUE Cougars, scoring 831 points in 52 games, an average of 15.98 points per game.