Firefighters battled a grass fire near Refugio Canyon from the ground and the air Monday afternoon before containing it to 10 acres, according to the Santa Barbara County Fire Department.
Fire Capt. David Sadecki said Tuesday that the fire started when a bird caused an electric arc that ignited the vegetation around the support line anchor.
He said investigators determined the fire originated at the base of one of the power poles where the support line is anchored into the ground.
The blaze was reported shortly before 4:30 p.m. on the inland side of Highway 101, west of Refugio Canyon Road, according to Sadecki.
It was declared contained at 7 p.m., although crews remained on scene for several hours doing mop-up, Sadecki said.
Eight county fire engines, two water tenders, three bulldozers and two hand crews were dispatched to the scene, along with two air tankers dropping fire retardant, and two water-dropping helicopters, Sadecki said, adding that U.S. Forest Service firefighters were helping battle the fire.
Flames were burning uphill, mostly in grass, in an area that was steep and difficult for firefighters to access, Sadecki said.
One structure was threatened, but was not damaged, and no evacuations were ordered.
No injuries were reported.
Highway 101 remained open in both directions, although traffic was slowed in the area of the fire.