KALAMA, Wash. — A woman who was killed in a fiery semi-truck crash along Interstate 5 in southwest Washington more than 35 years ago has finally been identified, solving a mystery that stretched across decades and thousands of miles.
The Washington State Patrol announced Thursday that the woman investigators had known for decades as “Helen Doe” was Mary Ellen “Mollie” McCullough, who disappeared in 1991 at the age of 34.
McCullough died on May 14, 1991, when two semi-trucks collided on southbound I-5 in Kalama, according to WSP. The crash sparked a severe fire, killing Missouri truck driver Lester Harvel and a female passenger riding in one of the trucks. Investigators could not identify the woman.
With Mount St. Helens visible from the crash scene, investigators began calling the unidentified woman “Helen Doe.” She was ultimately buried in an unmarked grave in Longview.
At the time, McCullough’s family did not know she had made it to Washington. WSP said she had left home to catch a ride in 1991 and was never heard from again. Her family continued looking for her, but according to the agency, they could not get her name added to missing-person lists. When she failed to appear at her grandmother’s funeral in 1993 and her mother’s funeral in 1994, relatives increasingly feared she had died.
The case remained unresolved for decades.
In 2014, Greg Wilcoxson, now a retired WSP detective, and Detective Sgt. Stacy Moate reopened the investigation as improvements in DNA technology offered another chance to identify the woman. Investigators worked with the Cowlitz County Coroner and other organizations to have the remains exhumed. A forensic artist also produced sketches in an effort to generate leads.
Investigators initially believed “Helen Doe” may have been Native American, based on witness statements and information from a forensic anthropologist. However, a more advanced DNA profile produced by Othram Labs in 2022 indicated she had Scottish, Irish and English ancestry. That profile was uploaded to FamilyTreeDNA.com and used in a forensic genealogy investigation.
The breakthrough came Aug. 6, 2026.
Moate called Michael McCullough, whose name appeared on a list of potential relatives developed through the DNA research. She asked whether he knew of a woman in his family who had disappeared in the early 1990s.
“Yes. That would be my sister — Mollie,” he told her, according to WSP.
Additional DNA testing over the following weeks confirmed that Michael McCullough was the brother of the woman investigators had called “Helen Doe.”
The discovery gave the family an answer to a question they had been living with for 35 years.
“Her family had wanted to find her, and they loved her and they were so thankful to finally have answers,” Moate said. “They all knew that she had to have died but they were thankful to know that it was not by homicidal means and that she did not suffer.”
McCullough’s family now plans to have her cremated remains returned to Cambridge, Ohio, where she was born.
Her brother said the family is grateful to the investigators, scientists and community members who continued working to identify her over the decades.
“From the bottom of our hearts, thank you for never giving up on our Mollie,” he said.
©2026 Cox Media Group
