Yellowstone National Park is the centerpiece of the Greater Yellowstone Ecosystem, the largest intact ecosystem in the Earth's northern temperate zone. Yellowstone became the world's first national park on March 1, 1872. Located mostly in the U.S. state of Wyoming, the park extends into Montana and Idaho. The park is known for its wildlife and geothermal features; the Old Faithful Geyser is one of the most popular features in the park.
More than 1,000 sites of historical significance have been discovered. Native Americans have lived in the Yellowstone region for at least 11,000 years. The region was bypassed during the Lewis and Clark Expedition in the early 1800s. Aside from visits by mountain men during the next early to mid-1800s, organized exploration did not begin until the late 1860s. The U.S. Army was commissioned to oversee the park just after its establishment. In 1917, administration of the park was transferred to the National Park Service, which had been created the previous year. Hundreds of structures have been built and are protected for their architectural and historical significance. |