Margaret Key's body was found at around 2 p.m. this afternoon in the 1800 block of Mount Veeder Road, Sgt. Doug Pace said.
Key's car was spotted by a UPS driver, who reported it to volunteers who were searching the area. The searchers notified the sheriff's office, Pace said.
Key's 2001 Buick LeSabre was found off the road and appeared to be stuck in the mud. Her body was found outside the car "a little ways away in the woods," Pace said.
While the cause of death is under investigation, Pace said there were no signs of foul play.
"It looks like she got confused," he said.
Key was last seen leaving her home on Hagen Road around 5:30 p.m. She was driving to a bridge game at a home in the Browns Valley area of the city of Napa, sheriff's Capt. Tracey Stuart said.
She never showed up at the card game and didn't return home around 9:30 p.m. as expected, Stuart said.
Key stopped to ask directions at the Browns Valley Market at 3263 Browns Valley Road, about a mile from the home where the card game was held, Stuart said.
Airplanes from the California Highway Patrol and the sheriff's office searched for Key on Saturday and Sunday, and searchers were walking along roads today to see if the Buick drove into a ditch, Stuart said.
Key was not carrying her cellphone, Stuart said.
Key did not have any acute medical conditions and had never disappeared before, but had previously become lost or disoriented, Stuart said.
