Nielsen v. Oregon

Background

Congress made the Columbia River the common boundary between Oregon and Washington and gave both States shared authority over the river. A person was acting on the Washington side under a Washington license, but Oregon prosecuted under its own law that forbade the same activity. The dispute reached the Supreme Court after Oregon’s highest court upheld the prosecution.

Reasoning

The Court considered whether, when both States have "concurrent" or shared authority over the river, one State may punish a person for doing on the other State’s side something that the other State expressly allowed. The Court explained that concurrent jurisdiction means each State can apply its laws on the river, but it does not allow one State to override the other’s clear authorization. The opinion distinguished acts that are inherently wrong (malum in se), where one State’s judgment may be final, from acts forbidden only by statute (malum prohibitum). Because the person acted within Washington’s territorial limits under Washington’s license, Oregon could not lawfully prosecute or punish him for that act.

Real world impact

This ruling prevents a State from using shared river authority to negate another State’s licensing and leaves some questions open — for example, what if the act occurred inside Oregon or if Washington had not authorized it. The Supreme Court reversed the Oregon decision and sent the case back for proceedings consistent with this opinion.