Valerie Ann Warshay was on a hiking trip in Hawaii when she vanished more than 40 years ago.
Now police are looking for any new leads in the case.
They say she was killed a few weeks after arriving on the Big Island from San Mateo County.
Her body was found at a park in Kalapana on April 23, 1978.
Police say the 26-year-old had met numerous people and they've had a suspect in the murder, but they've never been able to prove it.
They are asking anyone who may have come across Warshay to contact the Hawaii Police Department.