2008 California wildfires
The 2008 wildfire season was one of California's most devastating in the 21st century. While 6,255 fires occurred, about two-thirds as many as in 2007, the total area burned— 1,593,690 acres (6,449.4 square kilometres)—far exceeded that of previous years.
Source: Wikipedia — 2008 California wildfires (CC BY-SA 4.0)