The "El Portal" wildfire that flared up several days ago from unknown causes had burned more than 3,000 acres along Yosemite National Park's western border by Tuesday and was just 19 percent contained, but the park remained open for visitors.

Some access was constricted, as the Big Oak Flat Road that connects Highway 140 to Highway 120 to the Yosemite Valley floor has been closed by the fire. Visitors traveling Highway 120 were being told to use the Highway 49N detour to reach the valley and southern portions of the park, such as Wawona.

The fire, which was spotted about 5 p.m. PDT on Saturday, was being battled by nearly 650 fightfighters. They were enduring temperatures hovering near 100 degrees and faced "extremely steep and remote terrain" covered with chaparral, grasses, and pine and oak woodlands in places.

"The significant natural resources of Merced Grove Giant Sequoia within Yosemite National Park is threatened. The Big Oak Flat Road between State Highway 120 and Yosemite Valley is closed during peak visitor season creating a major impact to the local economy of the gateway communities of Yosemite National Park and limits visitor access to the park itself," the daily fire report read.

Despite the fire, all entrances to the park were open, according to area tourism bureaus. Yosemite Valley, Mariposa Grove, and Glacier Point were accessible from Highways 140 or 41, while the high country was accessible from Highway 120.

“The park and the historic towns leading into the park are open and welcoming visitors, but visitors should check ahead depending on the area they’d like to enjoy,” said Terry Selk, executive director of the Yosemite/Mariposa Tourism Bureau. “From Highway 120, instead of driving from Yosemite Valley to Tioga Pass through the park, the detour created by the closure of Big Oak Flat Road sends visitors through historic California gold towns, such as Bear Valley and Coulterville.”