Raging wildfire forces more closures at Yosemite National Park The fire had blackened about 12,000 acres in the northwest corner of Yosemite on Saturday, up 1,000 acres from the day before, said Yosemite spokesman Scott Gediman. It was consuming brush, oaks and pines and threatened some giant sequoia trees in the park. Officials have closed parts of the park's northwestern edge throughout the week, including the Hetch Hetchy Reservoir area, Lake Eleanor and Lake Cherry. The fire on Saturday remained about 4 miles west of the reservoir and more than 20 miles from Yosemite Valley, the park's main tourist centre, Mr Gediman said. Daniel Berlant, a spokesman for the California Department of Forestry and Fire Protection, said crews were making progress but the steep terrain in the area "definitely has posed a major challenge." The fire was threatening power and water supplies to San Francisco about 200 miles to the west. California Governor Jerry Brown on Friday declared a state of emergency for San Francisco, saying the fire had damaged the electrical infrastructure serving the city and forced the local Public Utilities Commission to shut down power lines. The Hetch Hetchy Reservoir provides water to 2.6 million customers in the San Francisco area and Mr Brown in his declaration said the city's water supply could be affected if the blaze harms the reservoir. The reservoir provides about 85 per cent of San Francisco's water needs and has not been disrupted by the fire, said Tyrone Jue, spokesman for the San Francisco Public Utilities Commission. San Francisco could draw on water from neighbours if the supply is compromised, he said. Mr Berlant, the forestry spokesman, said about 2,700 firefighters were expected to be on the front lines on Saturday to fight the fire, which started on Aug. 17 in the Stanislaus National Forest. Yosemite, one of the nation's major tourist destinations, attracted nearly 4 million visitors last year.