Santa Barbara County firefighters battled a stubborn wind-driven grass fire that threatened homes near the town of Santa Ynez Tuesday afternoon before being corralled.

On Wednesday morning, authorities said investigators determined that the cause of the fire was accidental, and that it was related to two power lines making contact during high winds.

Fire crews were called out at about 3:25 p.m. Tuesday to the area of Highway 246 and Meadowvale Road, according to fire Capt. David Sadecki.

The blaze, which started out burning just a couple acres of grassland, charred some 170 acres before firefighters were able to stop the forward spread, Sadecki said.

It was declared contained about 8 p.m., but fire crews remained on scene throughout the night keeping an eye out for hot spots.

Several rural neighborhoods in the surrounding areas were advised by reverse notification calls through the 9-1-1 system about the fire danger, but no evacuations were ordered, and residents eventually were told the danger had passed.

Two county helicopters responded initially, and additional firefighting aircraft — including four air tankers and two more helicopters — were diverted from the White Fire farther up the valley to assist in the fire fight, Sadecki said.

Some 50 structures in the area were threatened by flames at one point, Sadecki said.

Winds pushed the fire toward Highway 246, and the flames jumped the roadway at about 4:20 p.m.

Highway 154 was shut down at Armour Ranch Road and Edison Street, and Highway 246 was closed at Meadowvale, but both eventually were reopened to traffic.

No injuries were reported, Sadecki said.

— Noozhawk executive editor Tom Bolton can be reached at tbolton@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.