"The largest wildfire in the United States continued its destructive march through the Sierra Nevada on Tuesday, pushing further into Yosemite National Park and for the first time burning nearly to the edge of Hetch Hetchy Reservoir, the linchpin of the water supply for 2.6 million Bay Area residents from San Francisco to Silicon Valley."
"Flames from the Rim Fire -- which reached 184,481 acres -- also forced the closure of several miles of Yosemite's famed Tioga Road on Tuesday afternoon. The fire advanced to within 300 yards of the Hetch Hetchy Reservoir's southern edges, and ash is accumulating on the water's surface, said Harlan Kelly Jr., general manager of the San Francisco Public Utilities Commission, which owns the reservoir.
'It is an emergency,' Kelly said. 'We are taking it seriously. We are very concerned.'"