Thick smoke that held down winds and temperatures began to clear Sunday from the scenic forestlands of Northern California as firefighters battling the largest single wildfire in state history braced for a return of fire-friendly weather, writes ABC.

Fueled by strong winds and bone-dry vegetation, the Dixie Fire has grown to become the largest single wildfire in state history. Destroying homes and businesses, the fire, burning in Butte, Plumas, Lassen, and Tehama counties has burned a total of 489,287 acres and is 21% contained.

The Plumas County Sheriff’s Office said four people from Greenville remain missing at this time.