Hurricane-force winds combined hundreds of small fires in the U.S. states of Washington and Idaho into the Devil's Broom fire, which burned about 4,700 square miles (12,100 km²), the largest fire in recorded U.S. history.

Washington, officially the State of Washington, is a state in the Pacific Northwest region of the United States. It is often referred to as Washington State to distinguish it from the national capital, both named after George Washington. Washington borders the Pacific Ocean to the west, Oregon to the south, Idaho to the east, and shares an international border with the Canadian province of British Columbia to the north. Olympia is the state capital, and the most populous city is Seattle.

Idaho is a landlocked state in the Pacific Northwest and Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington and Oregon to the west; the state shares a small portion of the Canada–United States border to the north with the Canadian province of British Columbia. Idaho's state capital and largest city is Boise. With an area of 83,569 square miles (216,440 km²), Idaho is the 14th-largest state by land area. The state has a population of approximately two million people; it ranks as the 13th-least populous and the seventh-least densely populated of the 50 U.S. states.

The Great Fire of 1910 was a wildfire in the Inland Northwest region of the United States which burned three million acres in Northern Idaho and Western Montana in the summer of 1910, with extensions into Eastern Washington and Southeast British Columbia. The area burned included large parts of the Bitterroot, Cabinet, Clearwater, Coeur d'Alene, Flathead, Kaniksu, Kootenai, Lewis and Clark, Lolo, and St. Joe national forests. The fire burned over two days on the weekend of August 20–21, after strong winds caused numerous smaller fires to combine into a firestorm of unprecedented size. It killed 87 people, mostly firefighters, destroyed numerous manmade structures, including several entire towns, and burned more than three million acres of forest with an estimated one billion dollars' worth of timber lost. While the exact cause of the fire is often debated, according to various U.S. Forest Service sources, the primary cause of the Big Burn was a combination of severe drought and a series of lightning storms that ignited hundreds of small fires across the Northern Rockies. Ignition sources also likely included human activity such as from railroads, homesteaders, and loggers. It is believed to be the largest, although not the deadliest, forest fire in U.S. history.