Every year has its forest fire season. Eighty percent of wildfires are started by lightning strikes, while others are the result of arson and carelessness. The larger fires can burn through millions of acres of forestland, traveling rapidly in strong winds from treetop to treetop. Fire-generated winds can top 120 mph, and flames can soar 300 feet high. In this screensaver you will see 50 amazing pictures taken by the U.S. National Park Service of numerous forest fires that raged in western states.