The Pickett Fire doubled in size overnight as firefighters struggled to reach the remote, steep rugged terrain where it was burning in the North Bay, authorities said.

Air quality reached “very unhealthy” levels in parts of the region Friday afternoon as smoke spread from the growing Pickett Fire.

The North Bay will see hazy skies for the next several days due to smoke from the Pickett Fire burning in Napa County near Calistoga​, air quality officials said Monday.