US President George W. Bush offered federal help and encouragement Thursday to some of the 25,000 firefighters working under a blazing sun to contain wildfires that make up the single largest fire event ever recorded in California. Since a huge lightning storm on June 21, about 2,010 separate fires have ignited across California, ravaging nearly 900,000 acres (364,225 hectares). Gov. Arnold Schwarzenegger declared a state of emergency in 12 counties affected by the wildfires and has called in the California National Guard to help. In Redding, in the northwest corner of the state, Bush was being briefed on the fires and meeting with a few dozen first responders and state and local officials. Afterward, the president and Schwarzenegger were taking an aerial tour to survey fire damage in the 2.1 million-acre (850,000 hectare) Shasta-Trinity National Forest, the largest in California. Briefing reporters aboard Air Force One during the flight from Washington, David Paulison, administrator of the Federal Emergency Management Agency, said a myriad of federal agencies have been participating in daily, one-hour video conferences with California officials to identify ways for the federal government to help the state.