The Oak Fire has now burned 16,791 acres of land and is only about 10% contained, California’s fire department said on Monday.
The blaze has forced the evacuation of over 6,000 people, many of whom have been staying in temporary shelters.
Firefighters are still combating the blaze in steep, rugged terrain.
Mariposa county has set up an emergency evacuation centre for those forced to flee.
There, the BBC saw rows of camp beds arranged in classrooms, with people playing games to try to take their minds of what might be happening to their homes.
As dusk approached on Sunday, the sky over the centre had turned yellow and orange, while a grey streak of smoke hung over the town. One resident remarked how “pretty” it looked, shaking her head.
Among those taking shelter there was Joy, who bought a home in the area during the Covid-19 pandemic. She decided to flee after seeing smoke and flames billowing from the hill where the house is located.
Joy managed to get her pets to safety – but still doesn’t know the condition of her dream home in the mountains.
“I’m just hoping I have something to go back home to,” she told the BBC.
Another evacuee, 10-year-old Taylor – who was in the area visiting her grandmother – recalled receiving an order to leave the area as she and her family were sitting down to eat pizza.
“It was so scary,” she said. “I just wanted to get out of there”.
At least seven structures have so far been confirmed damaged.
A further 3,271 buildings – both homes and businesses – were under threat as of late Sunday, the California Department of Forestry and Fire Protection (Cal Fire) reported.
The scale of the blaze marks an ominous start to California’s wildfire season and officials have warned that a combination of drought, climate change, and overgrown vegetation are posing significant challenges and increasing the chances of the fire spreading rapidly.
Much of the United States is sweltering through a heatwave and heat advisory warnings are in effect in more than a dozen states. Temperatures in Mariposa County hit 100F (38C) on Sunday, and are expected to stay high for the next few days.
Yosemite National Park, which lies to the north-east of where Oak Fire is burning, is home to some of the largest and oldest sequoia trees in the world. The redwoods were threatened by another blaze earlier this month, but firefighters managed to save them.
Climate change increases the risk of the hot, dry weather that is likely to fuel wildfires.
The world has already warmed by about 1.1C since the industrial era began and temperatures will keep rising unless governments around the world make steep cuts to emissions.
Several European governments have struggled to contain dozens of separate wildfires which have ripped across the continent in recent weeks.