A woman who said she fell asleep at the wheel overturned her Jeep at about 7:20 this morning. County Fire Battalion Chief Mike Snow said she was driving northbound on Old Woman Springs Road near Buena Suerte when the Jeep drifted over to the side of the road and hit a chain link fence. The driver lost control and the Jeep flipped over. Both occupants were out of the vehicle when firefighters arrived; they were taken to Hi-Desert Medical Center for evaluation.