Wyoming v. Oklahoma

From 1981 to 1988, mining companies operating in Wyoming (plaintiff) provided most of the coal used by four utility companies in Oklahoma (defendant). Wyoming imposed a severance tax on coal mined in the state. In 1988 Oklahoma passed a law (the law) requiring coal-powered generating plants to burn at least 10 percent Oklahoma-mined coal. Wyoming filed a lawsuit in the United States Supreme Court. Wyoming argued that the law violated the Commerce Clause of the United States Constitution because it caused Wyoming to lose severance-tax revenue, and Wyoming sought an injunction against enforcement of the law. Oklahoma opposed the lawsuit, arguing that Wyoming’s lost tax revenue was not a valid injury under the Commerce Clause. To support its argument, Oklahoma argued that the mining companies that operated in Wyoming were better suited to bring the case and presented evidence showing that Wyoming’s lost tax revenue accounted for less than 1 percent of its total tax revenue. Oklahoma also argued that the Court should decline to exercise its original jurisdiction over the case. The Court appointed a special master to oversee the case. Wyoming and Oklahoma both moved for summary judgment. After hearing arguments from Wyoming and Oklahoma, the special master recommended that the Court exercise its original jurisdiction and hold that the law violated the Commerce Clause.