Thousands of people fled the Dixie fire in northern California as it continued to spread over Saturday night, making it the second largest in state history.
By early Sunday it had destroyed 187,562 hectares, up from the previous day's 181,187ha.
It now covers an area larger than Los Angeles and about the size of the Hawaiian island of Maui.
Dixie is the largest active fire in the US, but one of only 11 major blazes in California.
Over the weekend it passed the 2018 Mendocino Complex fire to make it the second-worst fire in state history, authorities said.
The blaze, which on Saturday injured three firefighters, was 21 per cent contained on Sunday, unchanged from the day before, the CalFire website reported.
Crews estimate the fire, which began on July 13, will not finally be extinguished before August 20.
Weak winds and higher humidity were providing some help to firefighters, but they are bracing for temperatures expected to exceed 38°C by midweek.
Thousands of residents fled, with many finding temporary housing, even in tents, in the area, often unsure whether their homes survived.
On Saturday, the Plumas County Sheriff's office said it was searching for five people missing in Greenville. Another five people were confirmed found on Saturday.
The Dixie fire has already destroyed 404 buildings, gutting the historic town of Greenville, and CalFire said workers were being sent to try to save homes in the towns of Crescent Mills and Hunt Valley.
More than 5,000 personnel are battling the Dixie blaze.
By late July, the number of hectares burnt in California was up more than 250 per cent from 2020, the worst year for bushfires in the state's modern history.
The state's eight largest wildfires have all been since December 2017.
A long-term drought that scientists say is driven by climate change has left much of the western US and Canada parched, and vulnerable to highly destructive fires.