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".
The idea of the arch is attributed to Hiram Martin Chittenden, who felt that the area surrounding Gardiner was not sufficiently impressive and required an emphatic statement of arrival at the famous park.
Two towers or buttresses flank the main archway, pierced by pedestrian passages with heavy wood doors.
[4] The arch is flanked by curved walls of the same basalt stone, 12 feet (3.7 m) high, ending in short towers.
Similar panels flank the arch above the pedestrian doors, with "Yellowstone National Park" on the left and "Created by Act of Congress, March 1, 1872" on the right.