No U.S. national park starts with the letter U. The National Park Service lists 63 official national parks, from Acadia in Maine to Zion in Utah, and none of them has a name that begins with U. The letter is one of the rarest starting letters in the whole system, and that makes this list unusual.

The reason is mostly about how parks get their names. Most parks are named after a landform, a nature feature, or a local place, such as Yosemite, Yellowstone, or Glacier Bay. Few of these words start with U. Many names also come from Native American languages or from early explorers, and very few of those words begin with this letter. Congress creates each park by law, and it tends to pick names that people already use for the place.

Some places come close to fitting the search. Utah is home to five national parks: Arches, Bryce Canyon, Canyonlands, Capitol Reef, and Zion. The state name starts with U, but the parks themselves do not. The National Park Service also runs other sites that start with U, such as the Upper Delaware Scenic and Recreational River, the USS Arizona Memorial in Hawaii, and the Ulysses S. Grant National Historic Site in Missouri. These are not national parks by official title, but they are part of the same park system and are good options for visitors who want to explore this letter.