Washington v. Oregon

Background

The dispute was between the State of Oregon and the territory (now State) north of it over where their boundary runs at the mouth of the Columbia River. The law admitting Oregon and Washington’s constitution use a starting point described as opposite the middle of the north ship channel. Early charts and testimony showed two channels at the river mouth and an island called Sand Island between them. Oregon later passed an 1864 act conveying Sand Island and nearby land to the United States, reflecting an understanding that the north channel marked the boundary.

Reasoning

The Court asked whether the state line should be the middle of the north channel named in the admission language or whether it should move to the center of whatever channel later became the main one. The Court found that Congress had specified the north channel’s middle as the boundary. That prescription stands even if river shifting makes the south channel later more used. The Court explained that slow, natural buildup or loss of land in the same named channel (gradual change) affects the line only within that channel, but the line does not jump to a different channel simply because use patterns change.

Real world impact

The decision fixes the state boundary along the center of the north ship channel as written, preserves Oregon’s title claims tied to Sand Island, and prevents ownership or jurisdiction from moving to the south channel just because navigation patterns altered. Costs in the case were divided equally.