https://www.nps.gov/yell/planyourvisit/parkfacts.htm "Park Facts" https://www.nps.gov/yell/planyourvisit/parkfacts.htm "Park Facts" Yellowstone National Park Facts. https://www.nps.gov/yell/planyourvisit/parkfacts.htm 2,221,766 acres 3,500 square miles world's first national park 2.2-million-acre of land Rhode Island and Delaware combined 3,472 square miles https://www.nps.gov/yell/planyourvisit/parkfacts.htm 3,500 square miles https://www.nps.gov/yell/planyourvisit/parkfacts.htm « Park Facts » Park Facts https://www.nps.gov/yell/planyourvisit/parkfacts.htm 3,500 square miles https://www.nps.gov/yell/planyourvisit/parkfacts.htm Park Facts 4 million annual visitors Yellowstone National Park 3,472-square-mile park 3,500 square miles Park Facts « Park Facts » https://www.nps.gov/yell/planyourvisit/parkfacts.htm 2,221,766 acres https://www.nps.gov/yell/planyourvisit/parkfacts.htm https://www.nps.gov/yell/planyourvisit/parkfacts.htm "Park Facts" https://www.nps.gov/yell/planyourvisit/parkfacts.htm https://www.nps.gov/yell/planyourvisit/parkfacts.htm Servicio de Parques Nacionales complete list of park facts Park Facts https://www.nps.gov/yell/planyourvisit/parkfacts.htm https://www.nps.gov/yell/planyourvisit/parkfacts.htm Yellowstone National Park Facts.