Here is the opinion in Sturgeon v. Masica. An excerpt:

John Sturgeon would like to use his hovercraft in a national preserve to reach moose hunting grounds. The State of Alaska is fine with that; the federal government is not. Sturgeon’s case turns on which entity—state or federal—gets to decide the matter. On remand from the Supreme Court, we again conclude that the federal government properly exercised its authority to regulate hovercraft use on the rivers within conservation system units in Alaska.

Briefs:

Alaska Brief

Enviro Groups Brief

Federal Brief

Mentasta Traditional Village et al Brief

Sturgeon Brief