Dennis was born September 16, 1953 to Clair James and Esta Marie (Caraway) Oxenreider Seiberling. Dennis and Joanne were married on June 10, 1971. They had three children. He enjoyed spending time outdoors with his family, working on cars, and working with computers. At the time of his death he was employed by Wells Fargo as a computer programmer.

He is survived by his wife Joanne (Oberender) Oxenreider; son Tom (Tammy) Oxenreider of Laurens; daughters Michelle (Ron) Phipps of Indianola and Elizabeth (Mathew) Miner of Ankeny; his mother Esta Seiberling; sisters, Judy Barrington, Sharon Berkenbosch and Teresa Purdy all of Indianola and six grandchildren.