Vanishing Hitchhiker of Idaho's I 95

In the early 1970s, a woman named Laura was driving along I-95 when she saw the hitchhiker. She offered her a ride, and the woman got in the car, asking to be taken to a town called Bonners Ferry.
During the ride, the hitchhiker was silent and didn't respond to any of Laura's questions. When they arrived at the town, the passenger had vanished from the car without a trace.