Five separate fires along state Route 67 merged into a 30-acre brush fire today that threatened homes today north of Lakeside and prompted the closure of the highway.
Several small fires were first reported about noon near Slaughterhouse Canyon Road, according to the California Highway Patrol.
Firefighters found five fires with a quarter-mile stretch of the highway, all on the east side, Cal Fire Battalion Chief Nick Schuler said.
Schuler said the blazes soon merged and burned east toward San Vicente Reservoir. Homes were threatened for a time, but none were damaged and no one was injured.
The CHP and sheriff's deputies closed northbound lanes of Route 67 at Mapleview Street, and northbound lanes at Scripps Poway Parkway.
Five helicopters, four air tankers and 15 engine crews brought the flames under control around 1 p.m. Several other fire agencies assisted Cal Fire.
The cause of the fires is under investigation, but Schuler said, "we have no reason to suspect arson. Nothing is suspicious.''
He said accidental causes could include machinery or a vehicle's catalytic converter.
Authorities reopened most of the highway by about 1:20 p.m., but kept the northbound right lane closed while fire crews continued to douse hot spots.
