Rinehart was last seen in Kansas City, Missouri on April 18, 1980. She has never been heard from again. At the time of her disappearance, she was driving a 1972 Chevrolet half-ton pickup truck, olive green in color with a yellow hood and a yellow right front fender. The truck's vehicle identification number was CCE142J124632 and the Missouri license plate was numbered EX6-401.

Rinehart's husband's brother found her truck at the 707 Truck Stop at Interstate 70 and Highway 7 in Blue Springs, Missouri on May 19, 1980, over a month after her disappearance. The truck had apparently been towed to that location and had been there since at least May 1. Its transmission line had been cut. A shovel, a serrated knife, a rope and a woman's purse were inside the vehicle. There was no sign of Rinehart at the scene.

At the time of her disappearance, Rinehart was involved in a court case against her husband. She said she was afraid of him and alleged he had held a gun to her head. Rinehart communicated with truck drivers on CB radio in 1980; her handle was Wild Woman. Her case remains unsolved.