Northern California wildfire grows further after jumping highway

By Steve Gorman (Reuters) - California's biggest and fiercest wildfire of the year grew larger as it raged for a seventh day through drought-parched land north of Napa Valley wine country after jumping a highway that authorities hoped would slow its advance. The blaze, dubbed the Rocky Fire, has charred some 67,000 acres, destroyed more than 50 buildings and displaced thousands of residents since erupting last week in the rugged canyons and foothills east of the town of Clearlake, about 110 miles north of San Francisco. Nearly 7,000 structures, mostly homes, were listed as threatened, with more than 13,000 people placed under evacuation orders or advisories, according to the California Department of Forestry and Fire Prevention (Cal Fire). What sparked the Rocky Fire was uncertain, but the blaze is one of nearly two dozen conflagrations that erupted across the state following thousands of dry lightning strikes in recent days, the bulk of them in northern California. All of the blazes have been fed by thickets of vegetation left desiccated by four years of drought. Firefighters reported gains battling the Rocky Fire, which is 20 percent contained, as triple-digit temperatures abated and light rain fell Tuesday afternoon. But Wednesday's forecast was to bring hotter, drier conditions, Cal Fire said, "increasing the potential of extreme fire behavior". The number of structures listed as destroyed by the aggressive blaze would likely increase as damage assessment teams are able to access burned areas in coming days, the agency said. Property losses from the Rocky Fire stood at 24 homes and 26 outbuildings, Cal Fire said. Smoke from the blaze was visible up to 80 miles to the south in Napa, one of California's renowned wine-making regions. Cal Fire resources already were stretched with more than 10,000 firefighters on the front lines statewide and all off-duty personnel called back to work. At least 3,200 firefighters were assigned to the Rocky Fire alone, backed by 19 water-dropping helicopters, four air tankers and nearly 60 bulldozers, Cal Fire reported. The aggressive blaze jumped a state highway on Monday that crews had hoped would serve as a containment line, and a portion of that corridor, as well as another highway, remain closed, Cal Fire said. President Barack Obama was briefed on the fires on Tuesday, the White House said. Governor Jerry Brown declared a state of emergency late last week. No serious injuries have been reported from the Rocky Fire. But a U.S. Forest Service ranger from South Dakota died last Thursday in a separate, smaller fire in the Modoc National Forest near California's border with Oregon. (Additional reporting by Victoria Cavaliere, Writing by Steve Gorman from Los Angeles; Editing by Cynthia Osterman and Himani Sarkar)