At left, an area where both thinning and controlled burning took place before the Bootleg fire. At right, an area where no thinning or controlled burning took place.

In southern Oregon, The Nature Conservancy, the U.S. Forest Service and the Klamath Tribes set up what became one of the nation’s largest outdoor laboratories.

Instead of racks of test tubes, however, this laboratory was populated by thousands of acres of trees.