"This lake isn't crystal clear. It's a typical western Oklahoma lake with a lot of silt in it. The visibility is only 6 to 12 inches on a good day," Peoples said. "We'll consider it a mystery until we prove otherwise."
The sheriff said it was entirely possible that people simply drove into Foss Lake and drowned.
"We know that to happen, even if you know your way around. It can happen that quick," he added.
The sheriff said he was confident the dive teams had found the three boys because one of the cars was a Chevrolet Camaro that appeared to match the description of the vehicle the boys were in when they vanished in 1970. The other was a Chevrolet from the early 1950s.
"We thought it was just going to be stolen vehicles, and that's not what it turned out to be, obviously," Randolph said.
The origins of the second vehicle were less clear. It was found 50 feet from the end of a boat ramp.
Tim Porter of Enid said he believed the remains could be those of his grandfather, John Albert Porter, who disappeared along with two other people in 1969.
"Forty-something years of wondering who or why. If it is my grandfather in there, it's a gift," Tim Porter said.
The sheriff said Wednesday he was not sure whether the cars held five or six bodies. The state medical examiner's office believed the remains of six people were recovered.
The bones were being sent to the medical examiner's office for identification and to determine the cause of death.
Highway Patrol spokeswoman Betsy Randolph said divers had found three skulls as of Tuesday evening, and they planned to continue looking for more remains.
Authorities hoped the discoveries will offer some relief to families who may have gone decades wondering where a missing loved one was.
"We're hoping these individuals, that this is going to bring some sort of closure to some families out there who have been waiting to hear about missing people," Randolph said. "If that's the case, then we're thrilled."