The United States initiated an action seeking an interpretation of Indian fishing rights under treaties with Indian tribes of the Pacific Northwest.  The Court held that the language of the treaties securing a "right of taking fish . . . in common with all citizens of the Territory" was not intended merely to guarantee the Indians access to usual and accustomed fishing sites and an "equal opportunity" for individual Indians, along with non-Indians, to try to catch fish, but instead secures to the Indian tribes a right to harvest a share of each run of anadromous fish that passes through tribal fishing areas.  Thus, an equitable measure of the common right to take fish should initially divide the harvestable portion of each run that passes through a "usual and accustomed" place into approximately equal treaty and nontreaty shares, and should then reduce the treaty share if tribal needs may be satisfied by a lesser amount.  The Court also held that any state-law prohibition against compliance with the District Court's decree cannot survive the command of the Supremacy Clause, and the State Game and Fisheries Departments, as parties to this litigation, may be ordered to prepare a set of rules that will implement the court's interpretation of the parties' rights even if state law withholds from them the power to do so.