First Lieutenant Rybolt was a member of Headquarters Company, 3rd Battalion, 31st Infantry Regiment, 7th Infantry Division. He was listed as Missing in Action while fighting the enemy in North Korea on 1 December 1950. He was presumed dead on 31 December 1953. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Rybolt was awarded the Air Medal with 2 Oak Leaf Clusters, the Purple Heart, the Combat Infantryman's Badge, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation and the Republic of Korea War Service Medal.