Hugh Pickens DOT Com writes: Retuers reports that firefighters are battling to gain control of a fast-moving wildfire raging on the edge of Yosemite National Park that is threatening power and water supplies to San Francisco about 200 miles to the west. "We are making progress but unfortunately the steep terrain definitely has posed a major challenge," says Daniel Berlant, a spokesman for the California Department of Forestry and Fire Protection. "Today we're continuing to see warm weather that could allow this fire to continue to grow very rapidly as it has over the last several days." California Governor Jerry Brown has declared a state of emergency, warning that the fire had damaged the electrical infrastructure serving the city, and forced the San Francisco Public Utilities Commission to shut down power lines. The blaze in the western Sierra Nevada Mountains is now the fastest-moving of 50 large wildfires raging across the drought-parched U.S. West that have strained resources and prompted fire managers to open talks with Pentagon commanders and Canadian officials about possible reinforcements. Firefighters have been hampered by a lack of moisture from the sky and on the ground. "The wind today is going to be better for firefighting, but we are still dealing with bone dry grass and brush," says Tina Rose, spokeswoman for the multi-agency incident command. "This fire is very dynamic."