Firefighters have made significant progress against the Washburn fire, which began July 7 in Yosemite National Park and has burned nearly 5,000 acres.
As of Monday, the fire had scorched 4,911 acres and was 50% contained, mostly within Yosemite.
Crews were working to build containment lines as they battled dry and hot conditions, with temperatures in the 90s, and heavy fuels.
“Observed fire behavior has diminished by successful suppression activities in most portions of the fire’s growth,” fire officials said in a statement Monday. More than 1,500 personnel were assigned to the fire.
The fire has spread to the Sierra National Forest, which borders Yosemite to the south, prompting the closure of a northern section of the forest.
Late last week, the fire began burning through a remote canyon on the south fork of the Merced River, the U.S. Forest Service said.
The fire is affecting wilderness, roads and major recreation areas and will require “significant firefighting and forest resources,” the forest service said.
But just as the fire caused the closure of one area, another reopened.
Shortly after it began, the fire prompted the evacuation and closure of the Wawona camping and residential area of Yosemite, near an iconic grove of giant sequoias that fire crews saved.
The area was reopened Saturday to residents and property owners with restrictions.
It was still unclear when the area would reopen to the general public, park officials said.
