In the United States, it had been common practice since the late 1960s not to suppress natural forest fires. The "let it burn" policy assumed that forest fires would burn themselves out quickly, without causing much damage. However, in the summer of 1988, forest fires in Yellowstone, the most famous national park in the country, burned for more than two months and spread over a huge area, encompassing more than 800,000 acres. Because of the large scale of the damage, many people called for replacing the "let it burn" policy with a policy of extinguishing forest fires as soon as they appeared. Three kinds of damage caused by the "let it burn" policy were emphasized by critics of the policy.
First, Yellowstone fires caused tremendous damage to the park's trees and other vegetation. When the fires finally died out, nearly one third of Yellowstone's land had been scorched. Trees were charred and blackened from flames and smoke. Smaller plants were entirely incinerated. What had been a national treasure now seemed like a devastated wasteland.
Second, the park wildlife was affected as well. Large animals like deer and elk were seen fleeing the fire. Many smaller species were probably unable to escape. There was also concern that the destruction of habitats and the disruption of food chains would make it impossible for the animals that survived the fire to return.
Third, the fires compromised the value of the park as a tourist attraction, which in turn had negative consequences for the local economy. With several thousand acres of the park engulfed in flames, the tourist season was cut short, and a large number of visitors decided to stay away. Of course, local businesses that depended on park visitors suffered as a result.