FRAZIER PARK (CBSLA.com) — Classes at Frazier Mountain High School were canceled Thursday as a more than 3,500-acre wildfire continued to burn in Kern County.

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The Grand Fire, which was 15 percent contained as of 9 a.m., started Wednesday afternoon near Frazier Mountain Park Road and Interstate 5 in the Techachapi Mountains, a Kern County Fire spokesperson said.

It was unclear what sparked the blaze.

Six helicopters and seven airtankers were sent to the scene Thursday to assist ground crews. In total, there were approximately 1,000 personnel fighting the blaze.

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Officials say strong winds fueled the fire Wednesday, which was being fought by Kern, Ventura and Los Angeles county fire departments, as well as CAL Fire.

Hungry Valley State Park and the Piru Creek campground were evacuated. Falcon Way to Frazier Mountain High School and roads entering the park and campground have been shut down.

So far, no residents have been forced to evacuate.

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