Invoking the continuing jurisdiction of the federal district court that determined the portion of annually harvestable fish guaranteed to several indigenous peoples (“Tribes”) by essentially identical treaty clauses guaranteeing off-reservation fishing rights, several Tribes and the U.S. government sought to enforce a duty upon the State of Washington to stop building and maintaining culverts under State roads that harm fish habitat and, consequently, reduce the production of harvestable fish. The district court ordered the State of Washington to identify all state-owned barrier culverts and ensure those culverts allow fish passage (by differentiated deadlines depending on several ecological and economic considerations). The State of Washington appealed the district court decision on a number of grounds.
Although the State of Washington conceded that the Tribes’ treaty-based off-reservation fishing rights guarantee the right to take up to fifty percent of the fish available for harvest, the State argued that “the clause imposes no obligation on the State to ensure that any fish will, in fact, be available.” Id. at 962. Employing the established canon of construction of federal indigenous (“Indian”) law that counsels that treaties should be construed in favor of the Tribes or “in the sense in which they would naturally be understood by the Indians,” the Ninth Circuit Court of Appeals determined that the Tribes understood “not only that they would have access to their usual and accustomed fishing places, but also that there would be fish sufficient to sustain them.” Id. at 964. The Ninth Circuit reasoned quite simply that “the Tribes’ right of access to their usual and accustomed fishing places would be worthless without harvestable fish.” Id. at 965.
Because the Ninth Circuit found that (1) currently there is not enough harvestable salmon available to ensure the Tribes a moderate living, (2) the State’s culverts block roughly a thousand miles of streams suitable for salmon habitat, and (3) replacing or modifying those culverts (structures built to allow streams to flow under roads) to allow fish passage would produce several hundred thousand additional mature salmon each year, it decided that the State of Washington has violated and continues to violate its duty to the Tribes under the fishing clause of their treaties by building and maintaining barrier culverts. Accordingly, the Ninth Circuit affirmed the decision of the district court.
The U.S. Supreme Court affirmed the Ninth Circuit decision by an equally divided court on June 11, 2018. Note that this case is often referred to as the “culverts case.”