Forest Ecologist Wally Covington said several factors have led up to what he calls a crisis. In the late 1800s cattle overgrazed and left the landscape bare -- so no small plants to keep fires on the ground. For a long time fire was seen as the enemy, so forests grew thick.
Add in severe drought, warmer temperatures and high winds, and Covington said you have an explosive situation.
"You can’t buy enough fire equipment, you can’t hire enough firefighters when you have the landscape so loaded with fuel as we’ve got it today," Covington said.
Fire managers think about things like air pollution, water supply and saving homes when calculating the risks of fighting a blaze.
View additional photos from the U.S. Forest Service.
U.S. Forest Service Director Tom Harbour said there’s an art and science to making these tough decisions.
"Sometimes the accumulation of those decisions will run into tens of millions of dollars on some of these large complex fires and sometimes the accumulation of those decisions will be next to nothing if we’re in a wilderness situation," Harbour said.
But more and more people are moving to the woods. So often times fire managers draw a map, and on one side they suppress a blaze where there’s a community nearby. And on the other side they may let it burn into a rocky ridge where it puts itself out.