The man, who was not immediately identified, was hoisted into a Fire Department helicopter and transported to County-USC Medical Center in critical condition Thursday.
``He was in and out of consciousness,'' Fire Department spokesman Brian Humphrey said. ``If he had gone another day, he would have been close to death.''
The man told rescuers he had spent four days in Griffith Park.
The biker had a 10-inch laceration on his forehead, blood on his swollen knee and bruises in different stages of healing, suggesting he had been injured for several days and had crawled some distance through the woods, Humphrey said.
The man told rescuers he was riding a mountain bike, but the bike was not immediately found.
Authorities received reports of a man stranded on the north side of the park shortly before 9:30 a.m. About 40 firefighters and two helicopters converged on the area near Forest Lawn Cemetery, where they spotted the man waving at them, Humphrey said.
