W. Tanner Mahan was born on January 26, 1953, in Odessa, Texas. He started at Texas Tech University in 1961 and graduated with a BBA in Finance in 1965. While he was at Tech he was active with the Delta Tau Delta fraternity. He served in Vietnam as a 1st lieutenant with the 2nd Battalion, 26th Marine Regiment from January 1, 1969, through February 9, 1969. While in Vietnam, he served as a platoon commander on Go Noi Island in Quang Nam Province. During his service he was awarded the PurpleHeart, Combat Action Ribbon, National Defense Medal, Vietnam Campaign Medal, and Vietnam Service Medal. He is married to Carol Steele Mahan and has five children: Todd, Kelly, Wade, Jessica, and Jennifer.
