Sturgeon v. Frost refers to two cases heard by the Supreme Court of the United States, both of which deal with the regulatory authority of the National Park Service over lands in Alaska under the Alaska National Interest Lands Conservation Act (ANILCA). In the first case, Sturgeon v. Frost I, 577 U.S. ___ (2016), the Court ruled that the National Park Service may regulate only "public" lands in Alaska and remanded the case to the Ninth Circuit Appeals Court to decide whether the river in question, which is "submerged land," is "public" or "non-public" land. In Sturgeon v. Frost II, 587 U.S. ___ (2019), the Court unanimously ruled that the ANILCA defines navigable waters in Alaska as "non-public" lands and that they are exempt from the National Park Service's national regulations.