The helicopter reported hovering over Dog Barr Road in southern Grass Valley Wednesday was part of a contracted crew doing power line maintenance for Pacific Gas and Electric. The line work was described as proactive transmission line work in extreme-fire hazard areas by PG&E spokesperson Brandi Ehlers. The project, which involves suspending a worker from a helicopter, has been contracted to a third party with PG&E inspectors working along side, Ehlers said. The lines originate out of Rio Oso, which straddles Yuba and Placer counties near Hicks Road, east of Pleasant Grove Road, Ehlers said. The lines lead to the …