Wallow, 2011
Credit: Kevork Djansezian / Getty Images

The Place: Arizona and New Mexico
The Underlying Cause: Human activity
The Devastation: 538,000 acres burned
What Is Noteworthy about This Fire: This was the largest fire to ever occur in the lower 48, burning more area in five weeks than planned and unplanned burns in the Apache-Sitgreaves National Forests from the previous 25 years. No one was ever arrested in connection with starting this fire but human activity was officially blamed. According to Frederick, most fires are started by either lightning or people.