James Palmerson and Roselyn Marshall were found near the Colorado Mills Mall in Lakewood, Colo. at about 9:55 p.m. Tuesday, police said.
An agent from the Lakewood Police Department found the teens huddled in the back of the 2005 Honda Civic that had been taken from Palmerson's grandfather, according to police.
The weather in the parking lot was about 5 degrees, according to the agent, who said the teens were cold but safe.
Los Altos police are coordinating with the parents and guardians of the teens for their speedy return to California. There are no criminal charges pending at this time, police said.
Palmerson, who lives with his grandparents, apparently took his grandfather's car and wallet before going to pick up Marshall, who lives with her parents.
The two are believed to be romantically involved and apparently left town voluntarily, Los Altos police Sgt. John Kurges said earlier Tuesday.
"We don't think they knew each other more than several weeks," he said.
The teens had never been on a date and neither has a history of running away, but Palmerson's friends told police he had been packing things in a duffle bag and apparently planning for the past week or two to leave town, Kurges said.
