Firefighters worked to extinguish what started as a quarter-acre brush fire in the 13300 block of Little Tujunga Canyon Road, according to the Los Angeles Fire Department. The blaze was first reported around 5:40 a.m.
The blaze, dubbed the Marek Fire, quickly grew to 50 acres and was moving southeast, according to the U.S. Forest Service. As of around 9:20 a.m., the blaze was 50 percent contained.
The Los Angeles County Fire Department said structures in the Kagel Canyon area were threatened by the fire, though USFS officials tweeted there were no threats.
More than 150 firefighters helped battle the flames, including firefighters from L.A. County and the L.A. City fire departments.
"We do anticipate a short period of cooler temperatures and higher relative humidities, which in some respects offer a lot of help in terms of fire behavior," said Fire Chief Bob Garcia with the U.S. Forest Service.
Little Tujunga Canyon Road and Gold Creek Road were shut down as firefighters worked to contain the blaze.
No evacuation orders were immediately set and no injuries were reported.
However, the flames were cause for some concern for a number of ranches south of Gold Creek Road, but the fire chief said structure protection assets were watching and waiting.