A middle-aged mountain bike rider was airlifted out of Annadel State Park on Wednesday evening after he was found lying unconscious on a trail.
The unidentified man, who was thought to be in his late 50s or early 60s, may have suffered a heart attack.
He was found about 4:45 p.m. by a passer-by near the intersection of Marsh and Canyon trails, fire dispatchers reported.
The passer-by, who called 911, began CPR with the guidance of a dispatcher.
Paramedics managed to reach the unconscious man and to bring him down to a parking lot in Annadel. A REACH helicopter met the paramedics there and about 5:35 p.m. transported the man to Santa Rosa Memorial Hospital.