Businesses and farms lie in a zone of mandatory evacuations in the face of the Maria Fire, which has burned more than 8,700 acres between Santa Paul and Somis in Ventura County.

More than 500 firefighters are working to control the blaze, according to Ventura County Office of Emergency Services. As of Friday afternoon, the Maria Fire was zero percent contained.

“Firefighters are protecting critical infrastructure, including radio communications, high-voltage electrical power lines and local agricultural crops,” the office said on its website.

The site features a map where “Ventura County residents can find out if their home or business is under evacuation or subject to a public safety power shutoff” by typing in the address. It also has a link to a Southern California Edison page to submit claims for losses because of power shutoffs.

Twelve schools districts canceled classes on Friday because of the fire and smoke.

The Maria Fire started a little after 6 p.m. on Thursday, Halloween night. A red flag warning for the region has been extended to 6 p.m. Saturday because of winds and low humidity.