The bodies of a man and two dogs were pulled from Topaz Lake about 6:30 p.m. Friday after the man's Jeep rolled out into the water, sinking more than 200 feet from shore.
A witness said he heard the man start the Jeep and then a big splash.
Holbrook resident Richard Pike said he watched as the Jeep rolled deeper and deeper into the water until it started to float.
"At about 20 feet it started to nose down and then we could see the bubbles as it sank the rest of the way," he said.
The incident was reported to authorities at 3:20 p.m., but by the time they arrived it was too late to save the man or his dogs.
"The water's 40 degrees, there was no way anyone could have reached him in time," Pike said.
Pike said he knew the Topaz Lake man from fishing.
"We were talking to him yesterday," he said. "We caught a big fish and we were talking about that. Everybody knew him around here."
The accident happened at a lake access just south of Topaz Lake RV Park in Mono County. Pike said he believed the Jeep was under least 40 feet of water.
California Highway Patrol Sgt. Gloria Tellez said the man's identity is being withheld pending notification of next of kin.
An attempt to tow the Jeep out of the water was unsuccessful after the tow truck came up short of cable.
"We need to get more cable," Tellez said. "We had 150 feet and we needed 100 yards."
The effort to recover the vehicle will continue on Saturday.
Search and rescue boats from the East Fork Fire District, Mono and Douglas counties aided in recovering the man's body.
Tellez said the man and a woman had been on the lake fishing since about 7 a.m. Friday.
"They were in two vehicles and were wrapping up," Tellez said. "She told him to wait up while she got the other vehicle when the incident happened."
They were leaving the site when the incident occurred.
Pike said there appeared to be no attempt on the driver's part to stop the vehicle.
"I didn't see him move at all," he said.
Rescuers worked for three hours to recover the bodies of the man and his dogs.
About 40 rescue workers and law enforcement officers responded to the incident from Mono County Sheriff's Office, California Highway Patrol, East Fork Fire District, Douglas County Sheriff's Search & Rescue, Douglas County Sheriff's Office, Antelope Valley Fire Department, and Mono County Search and Rescue.
The Mono County Sheriff's Office and California Highway Patrol are investigating the accident.