SAN DIEGO (KABC) -- A Fullerton couple who mysteriously disappeared on Mother's Day was found in a remote and rugged area of the Los Coyotes Indian Reservation on Sunday after apparently getting lost.Off-roaders told police they saw a white car on the reservation near Warner Springs with a man and woman inside. The people inside turned out to be Cecil Knutson, 79, and Dianna Bedwell, 68.Knutson was found dead, and Bedwell was severely dehydrated and airlifted to an Escondido hospital, private investigator Irma Sanchez said.Bedwell told the San Diego County sheriff's investigators that they were trying to take a shortcut when they got lost and were trapped on a remote road. They survived on rain water, a pie and oranges."There was cups around. They were drinking rain water as it rained and they've been out there for all indications since around May 10th," Los Coyotes Tribal Police Chief Dave Sossaman said.Sanchez said the car was on an incline and had been surrounded by mud."We don't have any information as to any damage to the vehicle that would indicate there was an accident involving another vehicle. What we do know is that the vehicle was found in a position where it was at an incline, leading investigators to believe they may have been taken off the road somehow," Sanchez said.The couple had likely tried to walk their way back several times, but couldn't make it, Sossaman said. Knutson and Bedwell were last seen on surveillance video leaving Valley View Casino in San Diego County on May 10. They were expected to meet their son at his home in La Quinta in Riverside County, but never arrived.Knutson's death is a devastating loss for a family that's already suffered through tragedy. Bedwell's sister Sylvia Likens was tortured and then murdered by her caretaker about 50 years ago. Her murder has since been dubbed "the most terrible crime in Indiana history." "This is a very difficult time for them, so they're trying to gather themselves together, be available for Diana and, of course, they're grieving the loss of Cecil," Sanchez said of the couple's family.Knutson's exact cause of death has yet to be determined. The couple's son has previously said, however, that both parents are both diabetic and need insulin.Knutson and Bedwell were both retired school bus drivers and had been married for more than 25 years.