 From January 1946 until July 1947, the now Lieutenant Colonel Karch was the chairman of the Board of Review, Discharges and Dismissals in the Navy Department in Washington, D.C..He then became an artillery instructor at Quantico's Marine Corps Schools until September 1949, where he became a member of the directing staff at the Canadian Army Staff College.Transferred to the 10th Marines, 2nd Marine Division in December 1951, having left the directing staff in November, he commanded the 4th Battalion.