Looking for a freebie from Uncle Sam? Make your way to the nearest National Park Service, which is offering free admission Tuesday June 21 to more than 100 national parks that usually charge entrance fees. The fee-free day marks the first day of summer on June 21. There are other fee-free days remaining this year, including Sept. 24, which is called Public Lands Day, and Nov. 11-13, Veterans Day weekend. A complete list of national parks covered by the free entrance offer can be found at the link below. The list includes many of the system’s best-known parks, such as Grand Canyon in Arizona, Yosemite and Muir Woods in California, Rocky Mountain in Colorado, Everglades in Florida, Yellowstone and Grand Teton in Wyoming, Acadia in Maine, Cape Cod in Massachusetts, Arches, Bryce and Zion in Utah, and Shenandoah in Virginia.