Yellowstone National Park, Wyoming, Idaho, Montana, United States

The wildfires during the summer of 1988 were the largest in the history of the park. Approximately 793,880 acres (321,272 ha; 1,240 sq mi) or 36% of the parkland was impacted by the fires, leading to a systematic reevaluation of fire management policies. The fire season of 1988 was considered normal until a combination of drought and heat by mid-July contributed to an extreme fire danger. On "Black Saturday," August 20, 1988, strong winds expanded the fires rapidly, and more than 150,000 acres (61,000 ha; 230 sq mi) burned.
The expansive cultural history of the park has been documented by the 1,000 archeological sites that have been discovered. The park has 1,106 historic structures and features, and of these Obsidian Cliff and five buildings have been designated National Historic Landmarks. Yellowstone was designated an International Biosphere Reserve on October 26, 1976, and a United Nations World Heritage Site on September 8, 1978.
In 2010, Yellowstone National Park was honored with its own quarter under the America the Beautiful Quarters Program.