Groenenberg departed from her family's residence in the Compton, California area on November 1, 1973. A friend told authorities that Groenenberg walked to the highway near Modesto, California and began hitchhiking shortly afterwards. The friend saw Groenenberg enter a blue or green truck with an unidentified male driver. Groenenberg has never been heard from again.

Groenenberg's family moved from southern California to the Compton area several weeks prior to her disappearance. Her mother was diagnosed with scleroderma, a tissue disease, shortly after Groenenberg vanished. Her parents were forced to leave the Modesto area as a result of her mother's condition. Groenenberg's parents have continued to own her childhood home in the southern part of the state. Her mother said that they hoped Groenenberg might return to see her former residence. Her case remains unsolved.

Some agencies give Groenenberg's birthdate as October 14, 1957.