Roger Oppenhuizen was born in Grand Rapids, Michigan, in 1946. After completing college in 1968, he enlisted in the Army to stay ahead of the draft, and signed up for Officer Candidate School. He did his basic training at Fort Dix, New Jersey, and then trained as a combat engineer at Fort Leonard Wood, Missouri. The Army assigned him to Infantry OCS instead of Finance, so he decided not to enter the program, so he was sent directly to Vietnam as a combat engineer in May, 1969. In Vietnam, he served with D Company, 35th Engineer Battalion, which was based at Soc Trang in the Mekong Delta and working on constructing a two-lane highway connecting the Delta to Saigon. For the first three months, Oppenhuizen worked on constructing the highway. However, because he knew how to type, Oppenhuizen eventually moved up to the company headquarters first to replace the operations sergeant while he was on leave, and then to replace the departing company clerk.