When to get free entry into U.S. National Parks in August

The National Park Service officially turns 100 years old on August 25.

As part of the year-long celebration, NPS is granting free access to its more than 400 parks, preserves, historic sites, and monuments for a total of 16 days in 2016. The next period of free admission will be Thursday August 25 through Sunday August 28, followed by Saturday September 24 (National Public Lands Day), and Friday November 11 (Veterans Day).

The waiver includes entrance fees, commercial tour fees, and transportation entrance fees. Other fees, such as activities that require a reservation, camping sites, lodging, tours, concession, and other fees collected by third party vendors working within the park system are not included.

Related:A Guide to Kings Canyon National Park

Heres a list of the 127 parks that usually have entrance fees:

Alaska

• Denali National Park & Preserve

Arizona

• Casa Grande Ruins National Monument

• Glen Canyon National Recreation Area

• Grand Canyon National Park

• Lake Mead National Recreation Area

• Montezuma Castle National Monument

• Organ Pipe Cactus National Monument

• Pipe Spring National Monument

• Saguaro National Park

• Sunset Crater Volcano National Monument

• Tonto National Monument

• Walnut Canyon National Monument

• Wupatki National Monument

Arkansas

• Fort Smith National Historic Site

• Pea Ridge National Military Park

California

• Cabrillo National Monument

• Death Valley National Park

• Joshua Tree National Park

• Lassen Volcanic National Park

• Lava Beds National Monument

• Muir Woods National Monument

• Pinnacles National Park

• San Francisco Maritime National Historical Park

• Sequoia & Kings Canyon National Parks

• Whiskeytown National Recreation Area

• Yosemite National Park

Colorado

• Black Canyon of the Gunnison National Park

• Colorado National Monument

• Dinosaur National Monument

• Florissant Fossil Beds National Monument

• Great Sand Dunes National Park & Preserve

• Mesa Verde National Park Rocky Mountain National Park

• Rocky Mountain National Park

Florida

• Canaveral National Seashore

• Castillo de San Marcos National Monument

• Dry Tortugas National Park

• Everglades National Park

• Gulf Islands National Seashore

Georgia

• Chattahoochee River National Recreation Area

• Chickamauga and Chattanooga National Military Park

• Cumberland Island National Seashore

• Fort Pulaski National Monument

Hawaii

• Haleakal National Park

• Hawaii Volcanoes National Park

• Puuhonua o Hnaunau National Historical Park

Idaho

• Craters of the Moon National Monument & Preserve

• Yellowstone National Park

Indiana

• Lincoln Boyhood National Memorial

Maine

• Acadia National Park

Maryland

• Antietam National Battlefield

• Assateague Island National Seashore

• Chesapeake and Ohio Canal National Historical Park

• Fort McHenry National Monument and Historic Shrine

• Fort Washington Park

• Harpers Ferry National Historical Park

Massachusetts

• Adams National Historical Park

• Cape Cod National Seashore

Michigan

• Sleeping Bear Dunes National Lakeshore

Minnesota

• Pipestone National Monument

Mississippi

• Gulf Islands National Seashore

• Vicksburg National Military Park

Missouri

• Harry S. Truman National Historic Site

• Jefferson National Expansion Memorial

• Wilsons Creek National Battlefield

Montana

• Bighorn Canyon National Recreation Area

• Glacier National Park

• Little Bighorn Battlefield National Monument

• Yellowstone National Park

Nebraska

• Scotts Bluff National Monument

Nevada

• Death Valley National Park

• Lake Mead National Recreation Area

New Hampshire

• Saint-Gaudens National Historic Site

New Jersey

• Thomas Edison National Historical Park

• Morristown National Historical Park

New Mexico

• Aztec Ruins National Monument

• Bandelier National Monument

• Capulin Volcano National Monument

• Carlsbad Caverns National Park

• Chaco Culture National Historical Park

• Gila Cliff Dwellings National Monument

• Pecos National Historical Park

• White Sands National Monument

• Valles Caldera National Preserve

New York

• Eleanor Roosevelt National Historic Site

• Home of Franklin D. Roosevelt National Historic Site

• Martin Van Buren National Historic Site

• Sagamore Hill National Historic Site

• Saratoga National Historical Park

• Vanderbilt Mansion National Historic Site

North Carolina

• Wright Brothers National Memorial

North Dakota

• Theodore Roosevelt National Park

Ohio

• James A. Garfield National Historic Site

• Perrys Victory & International Peace Memorial

Oklahoma

• Fort Smith National Historic Site

Oregon

• Crater Lake National Park

• Lewis & Clark National Historical Park

Pennsylvania

• Allegheny Portage Railroad National Historic Site

• Fort Necessity National Battlefield

• Johnstown Flood National Memorial

• Steamtown National Historic Site

Puerto Rico

• San Juan National Historic Site

South Carolina

• Fort Sumter National Monument

South Dakota

• Badlands National Park

• Jewel Cave National Monument

Tennessee

• Chickamauga and Chattanooga National Military Park

Texas

• Big Bend National Park

• Fort Davis National Historic Site

• Guadalupe Mountains National Park

• Padre Island National Seashore

Utah

• Arches National Park

• Bryce Canyon National Park

• Canyonlands National Park

• Capitol Reef National Park

• Cedar Breaks National Monument

• Dinosaur National Monument

• Glen Canyon National Recreation Area

• Golden Spike National Historic Site

• Natural Bridges National Monument

• Zion National Park

Virgin Islands

• Christiansted National Historic Site

Virginia

• Appomattox Court House National Historical Park

• Assateague Island National Seashore

• Colonial National Historical Park

• George Washington Memorial Parkways Great Falls Park

• Manassas National Battlefield Park

• Petersburg National Battlefield

• Prince William Forest Park

• Shenandoah National Park

Washington

• Fort Vancouver National Historic Site

• Lewis & Clark National Historical Park

• Mount Rainier National Park

• Olympic National Park

West Virginia

• Harpers Ferry National Historical Park

Wyoming

• Bighorn Canyon National Recreation Area

• Devils Tower National Monument

• Grand Teton National Park

• Yellowstone National Park

Christopher Tkaczyk is the Senior News Editor at Travel + Leisure. Follow him on Twitter and Instagram at @ctkaczyk.

This article was originally published on TravelAndLeisure.com