Question: is the st louis arch a national monument

Answer: Yes, The Gateway Arch National Park, formerly known as the Jefferson National Expansion Memorial until 2018, is an American national park located in St. Louis, Missouri, near the starting point of the Lewis and Clark Expedition. The Gateway Arch and its immediate surroundings were initially designated as a national memorial by executive order 7523 on December 21, 1935, and redesignated as a national park in 2018. The park is maintained by the National Park Service (NPS).