The missing persons' list has doubled since earlier on Thursday.
The Camp Fire, which broke out a week ago in the drought-affected Sierra Foothills 280 kilometres north of San Francisco, has left at least 63 people dead.
Pacific Gas & Electric, commonly referred to as PG&E, the utility company in Northern California, may be responsible for the Camp Fire that's now burning Northern California. It was 40 percent contained as of Wednesday evening.
The inferno is one of the most lethal single wildfires in the United States since 1900.
Sheriff Kory Honea said the list of missing would continue to fluctuate as more names are added and others are removed, either because they turn up safe or come to be identified among the dead.
But he acknowledged it was possible some of the missing might never be found.
A police officer stretches crime scene tape around an area where human remains were found in a vehicle that was destroyed by the Camp Fire on November 15, 2018 in Paradise, California.
Most of the town - almost 12,000 homes and buildings - has been destroyed, and an army of firefighters, many from other states, joined the struggle to contain and suppress the flames.
It comes as the White House said Donald Trump will visit California on Saturday and meet people caught up in the disaster.
Two people were killed by the southern California Woolsey Fire and a third death in the area is being investigated to see if it is linked to the blaze.
Last weekend the US President blamed "gross mismanagement" of the forests for the fires, and threatened to withhold federal payments.
There has been an outbreak of norovirus at a shelter housing people who left their homes to escape the Camp Fire, according to a Butte County public health spokeswoman.
Some experts have called into question forest management methods.