Smoke from the Ferguson Fire was drifting into the Yosemite Valley on Sunday/NPS

A 4,000-acre fire burning in the Sierra National Forest to the west of Yosemite National Park brought smoke into the park and led to backups at the park's South and Big Oak Flat entrances, but otherwise the park was operating normally Sunday, according to staff.

"The most significant impacts to park visitors are the Highway 140 road closure from Midpines, near the Yosemite Bug Hostel, to El Portal," Yosemite spokeswoman Jamie Richards said in an email. "Visitors are encouraged to use alternative routes to enter the park. Due to the Highway 140 road closure, the South Entrance and the Big Oak Flat Entrance have experienced longer lines. Visitors should be prepared for long wait times entering Yosemite via the South Entrance and the Big Oak Flat Entrance."

The Ferguson fire was spotted Friday evening, and quickly grew in steep, mostly inaccessible terrain thick with timber and brush. Roughly 500 firefighters were battling the blaze; one was killed Saturday when the bulldozer he was operating rolled over on top of him. Just 2 percent of the fire was contained as of Sunday morning.

"Savages Trading Post and Ferguson Ridge Road, Cedar Lodge, and Redbud lodge were evacuated. Jerseydale and Mariposa Pines are under an evacuation order as of last night," the Forest Service said Sunday morning. "Crews are focused on securing fire line along Highway 140 and protecting structures threatened along the corridor. Structure protection engines have arrived and are setting up to protect home and business between Cedar Lodge area and Hite’s Cove. Additionally, crews are working to extend containment lines east on both the fire's north and south flanks.

"Firefighters are scouting ridgelines to the east up the South Fork of the Merced River toward Yosemite National Park. Firefighters are aggressively fighting the fire at locations where they have the high probability of success. However, they are challenged by extremely steep and hazardous terrain with limited road access," the agency added.

In Yosemite, all campgrounds and visitor facilities were open. The valley had been operating for the past day using generator power, said Ms. Richards, adding that commercial power was restored Sunday morning.

"There are visual impacts from smoke and visitors sensitive to smoke may want to limit strenuous activities outside," she said. All park facilities and ranger-led programs were continuing as normal. 

The Ferguson fire in the Sierra National Forest was causing some impacts on Yosemite National Park/NOAA