I want to travel to all the national parks. Here's an updated checklist!
xxxAcadia National Park	Maine
National Park of American Samoa	American Samoa
Arches National Park	Utah
Badlands National Park	South Dakota
Big Bend National Park	Texas
Biscayne National Park	Florida
Black Canyon of the Gunnison National Park	Colorado
Bryce Canyon National Park	Utah
Canyonlands National Park	Utah
Capitol Reef National Park	Utah
Carlsbad Caverns National Park	New Mexico
Channel Islands National Park	California
Congaree National Park	South Carolina
Crater Lake National Park	Oregon
Cuyahoga Valley National Park	Ohio
Death Valley National Park	California, Nevada
Denali National Park and Preserve	Alaska
Dry Tortugas National Park	Florida
Everglades National Park	Florida
Gates of the Arctic National Park and Preserve	Alaska
Glacier National Park (part of Waterton-Glacier International Peace Park)	Montana/Alberta
Glacier Bay National Park and Preserve	Alaska
Grand Canyon National Park	Arizona
Grand Teton National Park	Wyoming
Great Basin National Park	Nevada
Great Sand Dunes National Park and Preserve	Colorado
Great Smoky Mountains National Park	North Carolina, Tennessee
Guadalupe Mountains National Park	Texas
Haleakala National Park	Hawaii
Hawaii Volcanoes National Park	Hawaii
Hot Springs National Park	Arkansas
Isle Royale National Park	Michigan
Joshua Tree National Park	California
Katmai National Park and Preserve	Alaska
Kenai Fjords National Park	Alaska
Kings Canyon National Park	California
Kobuk Valley National Park	Alaska
Lake Clark National Park and Preserve	Alaska
Lassen Volcanic National Park	California
Mammoth Cave National Park	Kentucky
Mesa Verde National Park	Colorado
xxxMount Rainier National Park	Washington
North Cascades National Park	Washington
xxxOlympic National Park	Washington
Petrified Forest National Park	Arizona
Redwood National and State Parks	California
Rocky Mountain National Park	Colorado
Saguaro National Park	Arizona
xxxSequoia National Park	California
Shenandoah National Park	Virginia
Theodore Roosevelt National Park	North Dakota
Virgin Islands National Park	U.S. Virgin Islands
Voyageurs National Park	Minnesota
Wind Cave National Park	South Dakota
Wrangell-St. Elias National Park and Preserve	Alaska
Yellowstone National Park	Idaho, Montana, Wyoming
xxxYosemite National Park	California
Zion National Park	Utah