Park Founders - Arches National Park (U.S. National Park Service) John 'Doc' Williams was an early advocate for the creation of Arches. On April 12, 1929, President Herbert Hoover signed presidential proclamation No. 1875 reserving 1,920 acres in the Windows and 2,600 acres in the Devils Garden for the purpose of establishing Arches National Monument. Since that time, the park's boundaries have been expanded several times. In 1971, Congress changed the status of Arches to National Park, recognizing over 10,000 years of human history that flourished in this now-famous landscape of rock. Last updated: August 15, 2017.