Imsdahl joined Montana-Dakota Utilities in 1970 as a staff engineer at the Lewis & Clark Generating Station. He advanced through a number of positions and was named vice president-power supply in 1989. In 1991 he became vice president-energy supply. Imsdahl was named executive vice president of utility operations early in 2003, and later that year became president of both Montana-Dakota and Great Plains. He assumed responsibility as chief executive officer of both utilities in November 2004, and was named chief executive officer of Cascade when MDU Resources acquired that company in 2007. Imsdahl, a registered professional engineer, is a graduate of North Dakota State University with a B.S. in mechanical engineering, and participated in the management program for executives at the University of Pittsburgh. He and his wife, Lynn, live in Bismarck, and have two children and four grandchildren.
