Yellowstone National Park has the distinction of being the world’s first national park. With an area of 3,472 square miles (8,992 sq km), Yellowstone is the largest national park in the mainland United States. One of the continuing difficulties at Yellowstone and other national parks is that Yellowstone is not a self-contained ecosystem. Its boundaries were established through a variety of political compromises, and lands around the park that once provided a buffer against outside events are being developed. The experience of Yellowstone Park’s flora and fauna illustrates the need to manage entire biogeo-graphical areas to preserve natural conditions within a national park.
Cable, T. T. (2011). Yellowstone National Park. In Environmental Encyclopedia (4th ed., Vol. 2, pp. 1805-1807). Detroit: Gale. Retrieved from http://link.galegroup.com/apps/doc/CX1918701633/GVRL?u=61wa_corpus&sid=GVRL&xid=0658d8b1