Which US national park is the smallest by land area?

Gateway Arch National Park is the smallest U.S. national park by land area.

The park occupies about 192.83 acres along the Mississippi River in St. Louis, Missouri. Its centerpiece is the Gateway Arch, a 630-foot stainless-steel monument designed by Finnish-American architect Eero Saarinen and completed in 1965. The arch commemorates westward expansion and the Louisiana Purchase, while the park also includes the Old Courthouse and a museum beneath the monument.

The site was originally created in 1935 as the Jefferson National Expansion Memorial. Congress redesignated it as Gateway Arch National Park in 2018, making it the newest addition to the national-park system at that time. Its urban setting and emphasis on architecture and history make it very different from wilderness parks such as Yellowstone or Yosemite.

The “smallest” distinction refers to acreage, not importance, elevation, or visitor facilities. Gateway Arch National Park is less than 2% the size of the next-smallest U.S. national park, Hot Springs National Park. Mammoth Cave and Bryce Canyon are both far larger.