Foss Lake, Oklahoma (CNN) -- It wasn't supposed to turn into a cold case mystery -- or possibly solve a couple, for that matter -- when Highway Patrol Trooper George Hoyle took new sonar equipment out to an Oklahoma lake on a training mission last week.
But boy have things changed.
The discovery of two submerged cars -- probably there for decades -- and the six bodies inside them have folks in western Oklahoma wondering whether two old mysteries can now be put aside.
The biggest question remains unanswered. How did the cars -- which faced different directions -- come to be in the lake?
The cars turned out to be a 1969 Chevrolet Camaro and a 1952 Chevrolet, sitting just 50 feet from a marina and 12 feet underwater. Lake levels are now 13 feet below normal because of a drought.
Their discovery was certainly a surprise. Hoyle was testing the high-tech sonar on September 10 when he saw something he didn't expect at the bottom of Foss Lake.
"I noticed that they were cars with this side-scan sonar," he said. "It puts off a very good image and very detailed. I knew for a fact they were cars and they were pretty close to one another."
The cars appear to match the descriptions of the vehicles in two cases that have remained mysteries for decades.
Custer County Sheriff Bruce Peoples told KOCO that one of the cars, the Camaro, may have belonged to 16-year-old Jimmy Williams, a Sayre teenager who disappeared in 1970 with two friends: Thomas Rios and Leah Johnson, both 18.
The three teenagers went missing the night of November 20, 1970, when they went for a ride around Sayre in Williams' blue Camaro with a white top, according to the Doe Network, a volunteer organization that helps law enforcement solve cold cases.
Williams bought the used Camaro just six days before he went missing, and the muscle car was the envy of teenage boys at the time, said Dayva Spitzer, publisher of the Sayre Record and Beckham County Democrat newspaper.
Johnson was Native American and, according to Spitzer, was said to be a descendent of Sitting Bull, the legendary Indian chief who led defeated Lt. Col. George Custer in the Battle of Little Bighorn in 1876. Local residents regarded Johnson as an Indian princess, Spitzer said.
Williams and his two passengers were supposed to go to a football game, but they may have gone hunting instead, Spitzer said. Williams was a hunter, Spitzer said, and in fact, two rifles were found, rusted and corroded, in the Camaro.
The three teens never returned home. At the time, the family posted a $500 reward in the local newspaper for "information leading to the finding of Jimmy Williams and subsequent meeting his parents," with a phone number. Tipsters could collect, the ad says.
More recently, Williams' brother Gary, who works on an offshore oil rig, raised the reward to $10,000 in 2009, Spitzer said.
Tantalizing clues emerged this week: The Camaro was found with all four windows rolled down and appeared to have entered the water backwards.
The other car, a Chevy, was found with the driver's side door open.
Sheriff Peoples hasn't ruled out foul play, but he suggested this week that all six deaths were likely accidents.
Debbie McManaman said she believes the older car contains the remains of her grandfather, John Alva Porter.
Porter, then 69, was traveling in a green Chevy with a sibling, Alrie Porter, and friend Nora Marie Duncan, 58, on April 8, 1969, when they all went missing, said Mike Nance, regional system administrator for the National Missing and Unidentified Persons System.
McManaman said she used to bring her kids out to the lake to skip rocks. She said she had no idea that the answer and the clues to her grandfather's disappearance may have been just feet away underwater.
In fact, over the years, when she and her kids drove by the lake, they wondered aloud if grandpa was in the lake, she said. "Maybe that's where he's at," she said.
The year he disappeared had a lot of rain, perhaps allowing a deeper lake to hide its secrets better, she said.
Authorities didn't know what they had until Tuesday, when they sent down Darrell Splawn, a diver with the Highway Patrol's underwater search and recovery team.
And even then, it was tough to know anything for certain. Visibility is only about 4 inches at the bottom of the lake. There's lots of murky muck to sift through.
"You can't see anything," Splawn said. "You basically just go down there and feel with your hands. It's just a blind feel."
Still, he found a shoe, so they attached a tow cable and pulled the cars out.
"It didn't really cross my mind as to a body being in it," Splawn said. "It could have been a shoe, but whenever we brought them up to the shore ... you could see the skeletal remains in them."
A second search by the diver found a skull and a few other bones.
Positive identification of the bodies could take years, authorities warn. They'll try to match DNA evidence if possible. The DNA testing will take place at the University of North Texas Health Science Center, which already has DNA samples from Duncan's relatives, said spokesman J. Todd Matthews.
A muddy wallet and purse could hold some clues.
While the scientists look for answers, the troopers hope they've provided some peace of mind.
"We are very fortunate to get to help these people and give their family closure, for they have lost loved ones," said Trooper Hoyle, who talked to the brother of one person missing for more than four decades.
"They didn't know that they were kidnapped or how they'd become missing, but I do believe that we gave them some closure ... so that they can have some resolve and serenity in their own lives."
CNN's Ed Lavandera contributed to this report from Oklahoma. Ed Payne wrote from Atlanta and Michael Martinez from Los Angeles. Jason Morris and Phil Gast also contributed.