Nearly 35 years after a North Texas woman vanished after an argument with her husband, authorities have found skeletal remains believed to be those of the woman inside a pickup truck recovered from a lake.

A passer-by discovered the partially exposed 1970s-model Chevy truck in Lake Granbury after the lake's water level dropped, thanks to the state's ongoing drought, and revealed a portion of the vehicle. The truck was found far away from any road or parking lot near the lake, and investigators "don't believe it was an accident," Hood County Sheriff Roger Deeds said.

“Upon digging all through the afternoon into the night, we found a complete skeleton and some identifying information that was also in there that ties the skeleton and that truck to Helen Holladay," Deeds told the Star-Telegram.

Holladay was 45 years old when she disappeared in September 1979. She was declared dead in 1986, the report said. Her husband, Herman, was a suspect in her disappearance but was never charged. He has since died.

“Early on in the investigation, the husband was looked at as a suspect but he was never charged with a crime,” Deeds told the newspaper. “We never got any evidence to tie him to it.”

Deputies had responded to a call about a domestic disturbance at the Holladays' house the night she went missing in September 1979. Witnesses reported seeing Helen Holladay leaving the house, though there was not enough evidence to charge her husband, Deeds said.

Authorities have notified Holladay's two surviving daughters, but the results of DNA tests will likely take about two months. Helen Holladay’s daughter, Karen Boatwright Stuart told the Star-Telegram her stepfather was violent and abusive.

“My mother put her hand through the window trying to get away from their motor home. I don’t know this for a fact, but I’ve always thought that Herman Holladay did something to her,” Stuart said.

The truck was discovered Thursday by a Granbury city worker.

Deeds noted that investigators searched the lake numerous times following Holladay's disappearance, but the murky waters and the fact that the truck was covered in silt made it nearly impossible for divers to see.

KDFW-TV reported that crews searched the lake in 1996, when it was about 6 feet below normal. The state's latest record-breaking drought has brought the lake to its lowest levels in years.

“We’ve never stopped the investigation. It’s gone cold a number of times,” Deeds told the Star-Telegram. “We might never know what exactly happened to her but we’re going to be working on that, too.”

Initial inspection of the skeletal remains revealed no signs of trauma, but detectives can't yet say whether foul play was involved in her death, Deeds said.

"It's still too early in the investigation to rule in one direction or the other," he said, adding that a forensic investigator with the University of North Texas at Denton is expected to inspect the remains.

The Associated Press contributed to this report.

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