Postcard of the Roosevelt Arch at the north entrance photographed by Frank J. Haynes, no date. The Roosevelt Arch is a rusticated triumphal arch at the north entrance to Yellowstone National Park in Gardiner, Montana. Constructed under the supervision of the U.S. Army at Fort Yellowstone, its cornerstone was laid down by President of the United States Theodore Roosevelt in 1903. The top of the arch is inscribed with a quote from the Organic Act of 1872, the legislation which created Yellowstone, which reads "For the Benefit and Enjoyment of the People." Yellowstone National Park is a national park located primarily in the 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.