Yellowstone National Park Yellowstone National Park is a national park located primarily in the U.S. state of Wyoming, although it also extends into Montana and Idaho. It was established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872. Address: United States Area: 8,983 km² Management: U.S. National Park Service Phone: +1 307-344-7381 Found {programi.total} similar results ... {inkspot.topic}