yellowstone national park

noun

1. a park in NW Wyoming and adjacent parts of Montana and Idaho: geysers, hot springs, falls, canyon. 3458 sq. mi. (8955 sq. km).

noun

1. a national park in the NW central US, mostly in NW Wyoming: the oldest and largest national park in the US, containing unusual geological formations and geysers. Area: 8956 sq km (3458 sq miles)

Located in Wyoming.