James Colin Egan, who went by Colin, was 18 when he made a phone call from San Francisco on August 6, 1972, telling his family in Mequon, Wisconsin, he planned to hitchhike to Denver and then fly home. He never arrived in Denver and that call was the last time his family heard from him. He is described as a white male with blond hair, blue eyes, 5 feet 9 inches tall, about 130 pounds, wearing gold-rimmed glasses and with a slight deformity in his left hand from a prior accident.

Few details are available about his time in San Francisco or the initial investigation. The case remains an active missing person investigation with Wisconsin authorities, and age-progressed images have been produced by organizations such as the National Center for Missing and Exploited Children. His father, James F. Egan, later noted in his 1999 obituary that he had been preceded in death by his son Colin.

If anyone saw Colin in San Francisco or en route to Denver in August 1972, or has information that could help, please share what is known.