Established in 1905, the Forest Service is an agency of the U.S. Department of Agriculture. The Forest Service manages public lands in national forests and grasslands. Gifford Pinchot, the first Chief of the Forest Service, summed up the mission of the Forest Service— "to provide the greatest amount of good for the greatest amount of people in the long run." National forests and grasslands encompass 193 million acres of land, which is an area equivalent to the size of Texas.

Wildfire suppression in the United States has had a long and varied history. For most of the 20th century, any form of wildland fire, whether it was naturally caused or otherwise, was quickly suppressed for fear of uncontrollable and destructive conflagrations such as the Peshtigo Fire in 1871 and the Great Fire of 1910. In the 1960s, policies governing wildfire suppression changed due to ecological studies that recognized fire as a natural process necessary for new growth. Today, policies advocating complete fire suppression have been exchanged for those who encourage wildland fire use, or the allowing of fire to act as a tool, such as the case with controlled burns. Before the middle of the 20th century, most forest managers believed that fires should be suppressed at all times.[4] By 1935, the U.S. Forest Service's fire management policy stipulated that all wildfires were to be suppressed by 10 am the morning after they were first spotted.[5] Fire fighting crews were established throughout public lands, and generally staffed by young men during fire seasons. By 1940, firefighters known as smokejumpers would parachute out of airplanes to extinguish flames in remote locations. By the beginning of World War II, over 8,000 fire lookout towers had been constructed in the United States. Though many have been torn down due to increased use of airplanes for fire spotting, three are still used each year in Yellowstone. Firefighting efforts were highly successful, with the area burned by wildfires reduced from an annual average of 30,000,000 acres (120,000 km2) during the 1930s, to between 2,000,000 acres (8,100 km2) and 5,000,000 acres (20,000 km2) by the 1960s.[4] The need for lumber during World War II was high and fires that destroyed timberland were deemed unacceptable. In 1944, the U.S. Forest Service developed an ad campaign to help educate the public that all fires were detrimental, using a cartoon black bear named Smokey Bear. This iconic firefighting bear can still be seen on posters with the catchphrase "Only you can prevent forest fires".[8][9] Early posters of Smokey Bear misled the public into believing that western wildfires were predominantly human-caused. In Yellowstone, human-caused fires average between 6 and 10 annually, while 35 wildfires are ignited by lightning.  The policy began to be questioned in the 1960s, when it was realized that no new giant sequoia had grown in the forests of California, because fire is an essential part of their life cycle.[14] In 1962, Secretary of the Interior Stewart Udall assembled a Special Advisory Board on Wildlife Management to look into wildlife management problems in the national parks. This Advisory Board wrote what is now referred to as the Leopold Report, named after its chair, zoologist and conservationist A. Starker Leopold, which did not confine its report to wildlife, but took the broader ecological view that parks should be managed as ecosystems. The passage of the 1964 Wilderness Act encouraged the allowance of natural processes to occur, including fire.[13] Afterwards, the National Park Service changed its policy in 1968 to recognize fire as an ecological process. Fires were to be allowed to run their courses as long as they could be contained within fire management units and accomplished approved management objectives. Several parks established fire use programs, and policies were gradually changed from fire control to fire management. The Forest Service enacted similar measures in 1974 by changing its policy from fire control to fire management, allowing lightning fires to burn in wilderness areas. This included both naturally caused fire and intentional prescribed fire.[1] In 1978, the Forest Service abandoned the 10:00 am policy in favor of a new policy that encouraged the use of wildland fire by prescription.