(Twisp, WA)  --  Officials say the Okanogan Complex has grown to be the largest wildfire in Washington state history.  The five wildfires are reported to be covering more than 400 square miles, slightly more than last year's Carlton Complex fires.  The Okanogan fire is reported to be about ten-percent contained, but is still threatening five-thousand homes.  The National Weather Service says a Red Flag warning will continue for much of central Washington through this evening.