PORTLAND, Ore. (KOIN) — The disappearance and death of a teenage girl in the late 1970s is back in the public’s view as the Clark County Sheriff’s Office renewed their efforts to solve this case.

Sandra Renee Morden, who was 16 at the time she disappeared, was known to her friends as Sandy. In 1980, remains of a body were found in Clark County but weren’t identified as Sandy until a forensic genetic genealogy study was completed in 2019.

Sandy’s background

Investigators learned that Sandy was born in San Francisco, Calif. on April 29. 1962 to Andrew Bain Morden, who passed in 1999, and Kathryn Morden, who died in 1988. Both parents would have been in their 40s when their daughter disappeared.

Sandy and her family moved to Portland from the Bay Area in the late 1960s. After her parents’ divorce in 1971, Andy was given primary custody of Sandy. Kathryn, on the other hand, remained in touch with Sandy and is believed to have been living in the Portland area at the time of her daughter’s disappearance.

According to the sheriff’s office, Andy is believed to have been living at a mobile home/RV park near Leichner Rd. in Vancouver at the time of Sandy’s disappearance. Both he and Sandy were known to go to café-style restaurants in both Portland and Vancouver.

Police say that Andy’s job as a deckhand on tugboats operating on the Willamette and Columbia rivers caused him to be away from home for up to a week at a time, complicating his role as the primary caregiver. Due to his occupation, Andy would place Sandy in the care of others when he was out of town.

In 1975, Sandy frequently stayed with a family in SE Portland while attending Binnesmead Elementary. She also stayed with a family from Vancouver in 1975-76 while attending Gaiser Middle School, a family in the Burlingame neighborhood in Portland in 1976-77 while attending Wilson High School and a family in Newberg in the Summer and Fall of 1977 when she was registered to attend Newberg High School.

Sandy had long dark hair and was described as appearing older than her true age. She also loved horses, seeking out horse ranches and boarding areas. Additionally, she had a dog named Rusty at the time of her disappearance.

Clark County detectives say that they would like to hear from friends, acquaintances, neighbors, coworkers, fellow veterans and classmates of Sandy Morden and Andy Morden, particularly those who interacted with them in Vancouver in the 1970s. Persons with any information are urged to contact investigators at coldcase@clark.wa.gov or through the cold case tip line at 564.397.2036.