Page:John Sturgeon v. Bert Frost, in his official capacity as Alaska Regional Director of the National Park Service.pdf/37

Rh Since the National Park System’s creation in 1872, it has grown to include over 400 historic and recreation areas encompassing over 84 million acres. 54 U. S. C. §100101(b)(1)(A); 83 Fed. Reg. 2065 (2018). These areas provide habitat for 247 threatened or endangered species and received more than 325 million visitors in 2016 alone. Id., at 2065–2066.

The task of protecting this vast park system principally falls to the Park Service. In the National Park Service Organic Act (Organic Act), 39 Stat. 535, Congress entrusted the Service with regulating to leave the parks “unimpaired for the enjoyment of future generations.” 54 U. S. C. §100101(a). Congress empowered the agency to promulgate regulations “necessary or proper” for managing the Park System, including regulations “concerning boating and other activities on or relating to water located within [Park] System units.” §§100751(a), (b). The Service has carried out this charge by enacting a wide range of regulations, including the ban on hovercraft use at issue. See 36 CFR §2.17(e) (2018).

Wielding its Organic Act authority, the Service applies many park rules on federally owned lands and waters it administers, as well as navigable waters “within the boundaries of the National Park System.” See 36 CFR §§1.2(a)(1), (3). The title to lands beneath navigable waters, even within national parks, typically belongs to the States. Because park boundaries can encompass both federally and nonfederally owned lands and waters, this means that some nonfederally owned waters are subject to Service regulations—at least outside of Alaska. See ante, at 7–8.