Firefighters Battle Flames, Terrain, North of LA Firefighters had to battle terrain as much as flames as they worked to surround a wildfire entering its third day in harsh hills and mountains north of Los Angeles. Temperatures dipped Thursday and were expected to remain cool on Friday, but winds upwards of 20 mph continued to swirl, and much of the blaze that has blackened some 3,800 acres was in rocky, rugged, difficult-to-reach places, making containment a challenge. After a heavy aerial effort Thursday, the fire was 25 percent contained by nightfall. The fire broke out near Interstate 5 when temperatures were in the 80s, and though they've dropped to the 60s, winds were still a problem. "It's definitely gusty, but we're lucky, the winds are blowing away from homes," Kern County Fire Department spokesman Corey Wilford said. It would be better if we didn't have winds at all though. Lower temperatures are expected to persist into the weekend. The fire has spread to three counties, Los Angeles, Kern and Ventura, but burned in mostly populated areas and threatened no homes or buildings. A Kern County high school was closed as a precaution. The fire started early Wednesday afternoon for reasons that remain under investigation. It initially burned thick brush, seasonal grasses and sage, but then moved into the trees. Efforts on Thursday were focused on the southern edge of the fire.