Visibility approached zero in some parts of Alaska over the weekend of August 21, 2004, as thick smoke poured from wildfires burning in the state's interior. The National Weather Service issued a dense smoke warning for the region surrounding Fairbanks, and Alaska's Department of Environmental Conservation issued an air quality alert for the same region. According to the Environmental Protection Agency, the air quality in Fairbanks remains at hazardous levels. This true-color image shows how dense the smoke was on August 21, 2004. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on the Orbview-2 satellite observed the smoke arching across Alaska and over the Bering Strait. The smoke is so thick that the ground can't be seen. Alaska's intense fire season began in mid-June when lightning triggered a number of large fires.