The fire broke out on Friday evening near the park’s western edge, and evacuations orders and advisories are in place.
Daniel Swain, a UCLA climatologist, declared the fire is “likely to burn for many days and may eventually become a major threat” to the National Park.
One firefighter lost his life on Saturday morning and one of the main roads into Yosemite National Park, Highway 140, was closed.
More than 700 personnel are fighting the blaze, with more on the way.
Alex Olow, Public Information Officer at Sierra National Park, commented on the current situation and told Express.co.uk: “Today the fire has spread.
“It was 9868 acres this morning.
“At the moment two percent of the blaze is contained and 1080 structures are threatened.”
Evacuation advisories were extended to 15 miles southeast from the source of the fire, Savage’s Trading Post on Highway 140.
Mr Olow also claimed that because of the road closure, visitors of the Yosemite Park have three other entrances, but “thick layers of smoke have started settling in the valley”.
He added: “The blaze can definitely change the air quality for the visitors.”
A Red Cross evacuation centre was set up at the New Life Christian Centre on Cole Road in Mariposa.
So far, 25 people have been to the shelter.
The cause of the fire is yet to be known and currently under investigation.
The Information Officer of Sierra National Park said the high temperatures California is experiencing has increased fire danger.
According to The California Department of Forestry and Fire Protection, California has had its worst start to the fire season in a decade, with more than 220,421 acres burned so far.
US wildfires have already burned more than 3.3million acres this year, which is more than the year-to-date average of about 3million acres in the past 10 years.