Opinion of the Court
ANILCA,” thus indisputably subjecting it to the Service’s regulatory authority. Id., at ___ (slip op., at 15). And if the answer was “no,” we asked the Ninth Circuit to address whether the Service, on some different theory from the one just dispatched, could still “regulate Sturgeon’s activities on the Nation River.” Id.', at ___ (slip op., at 16).
The Ninth Circuit never got past the first question because it concluded that the Nation River is “public land[.]” See 872 F. 3d 927, 936 (2017). The court explained that it was bound by three circuit decisions construing that term, when used in ANILCA’s provisions about subsistence fishing, as including all navigable waters. Id., at 933–934. Accordingly, the court again rejected Sturgeon’s challenge. Id., at 936.
And we again granted certiorari. 585 U. S. ___ (2018).
II
We first address whether, as the Ninth Circuit found, the Nation River is “public land” under ANILCA. As defined, once again, that term means (almost all) “lands, waters, and interests therein” the “title to which is in the United States.” 16 U. S. C. §3102(1)–(3). If the Nation River comes within that definition, even Sturgeon agrees that the Park Service may enforce its hovercraft rule in the stretch traversing the Yukon–Charley. That is because the Organic Act authorizes the Park Service to regulate boating and similar activities in parks and other system units—and under ANILCA’s Section 103(c) those units include all “public land” within their boundaries. 54 U. S. C. §100751(a)–(b); 16 U. S. C. §3103(c); see supra, at 8–10.
But the United States does not have “title” (as the just-quoted definition demands) to the Nation River in the ordinary sense. As the Park Service acknowledges, running waters cannot be owned—whether by a government or by a private party. See FPC v. Niagara Mohawk Power
