Borden was last seen by her family in their hometown of Big Spring, Texas in October 1979. Borden traveled to California shortly thereafter and called her family from an unknown location in the state. Her loved ones sent her a plane ticket for a return flight back to Texas, but she never retrieved it. Borden was last seen in California on October 10, 1979; she has not been heard from again. One of her friends told Borden's family that Borden was living in Amarillo, Texas and working as a waitress, but the friend did not provide further information and this account has not been confirmed.

Borden had a tendency to hitchhike in 1979. Authorities believe that she may have been taken against her will. Both California and Texas authorities are handling the investigation.