YOSEMITE NATIONAL PARK, Calif. -- A wildfire on the outskirts of Yosemite National Park has grown to more than 15 square miles and has forced the shutdown of one access road into the west side of the park.
The U.S. Forest Service said Tuesday that about 2,500 structures were threatened north of Highway 120.
The Rim fire grew significantly to an estimated 2,500 acres by Monday evening. It's one of hundreds of fires that crews are battling across the West, though firefighters were able to contain the Bridges fire in Calaveras County, near Natural Bridges, a popular recreation area.
The Rim fire broke out Saturday about 3:15 p.m. Its cause remains under investigation, said Jerry Snyder, public affairs officer for the Stanislaus National Forest. Although there has been lightning in some areas, officials don't believe that sparked the fire.
"It's not the cause of this fire that we know of," Snyder said. "But the area where it started is very remote. There are no roads."
The community of Buck Meadows has been evacuated, as have several family camps, including the San Jose Family Camp in Groveland, Snyder said. On the Groveland community Facebook page, residents were offering one another places to stay or to board animals.
State Route 120 was shut down in both directions, blocking traffic in and out of the park.
The Central Valley Transportation Management Center issued an alert Monday afternoon, advising motorists to avoid the area if possible and watch out for fire equipment. Officials said there is no estimated time of reopening.
The park remains open and visitors can use State Route 140 and State Route 4.
Steep terrain and hot, gusty weather in the canyons made for grueling conditions. Snyder said he was waiting for an update from the fire team on the plan of attack.
The Associated Press and Modesto Bee contributed to this report.