Sonia (Sonja) Kay Redbird was 19 when she was last seen on January 1, 1975, in Dallas, Texas. Born and raised in Anadarko, Oklahoma, she had moved to Dallas in 1972 and stayed in regular contact with her family until all communication stopped in 1975. Sonia was an enrolled member of the Kiowa Tribe and was described as about 5 feet 0 inches to 5 feet 4 inches tall, 130 to 140 pounds, with brown hair and brown eyes.

Her family later had her declared deceased through the Kiowa Tribal Court, but the circumstances of her disappearance remain unclear. The case is classified as endangered missing and is still open; investigators from the Kiowa Tribe, the Bureau of Indian Affairs, and local law enforcement continue to seek information. If anyone knew Sonia, lived near her in Dallas, or has information about her movements after January 1, 1975, please come forward.