Free 2021 National Parks and Federal Recreational Lands Annual Pass for Military

https://www.nps.gov/planyourvisit/passes.htm -Current U.S. military members and their dependents can get free National Park access with the Military pass that can be obtained at these federal recreation sites that issue passes.
https://www.nps.gov/planyourvisit/veterans-and-gold-star-families-free-access.htm -Veterans and Gold Star Families can also get free national park access, with more info at that link.