Oregon Public Broadcasting

The Bonneville Power Administration says vandals caused $40,000 of property damage near Coos Bay. The federal electric utility runs Oregon's dams and transmission grid.

Lineman in helicopters monitor BPA's thousands of miles of power lines for damage. Three times in the past six months they've found insulators damaged by gunfire on a high voltage transmission line near Lakeside Oregon. 18 insulators have been damaged.

BPA spokeswoman Katie Pruder says the vandals have put themselves and repair crews in serious danger.  

Katie Pruder: "When you consider that those insulators are the things that keep the electricity from jumping out onto the ground, you can imagine that its extremely dangerous to be shooting at those things."

Earlier this year gunshots also damaged a nearby fiber optic line. BPA is offering rewards for information about the incidents.