Oklahoma v. Texas

Background

This case settles a long-running dispute between Texas on one side and Oklahoma together with the United States on the other over where the Red River forms their boundary from the 100th meridian eastward to eastern Oklahoma. The parties disagreed about whether the border was the middle of the river, the low-water line, the foot of the bluffs, or the river’s bank. The Court previously ruled the boundary was along the south bank rather than the river’s middle, so the recent hearing focused on what “south bank” meant in this landscape of wide sandy beds, shifting channels, and surrounding bluffs.

Reasoning

The Court held that the treaty intended a bank boundary and defined the south bank as the water-washed, relatively permanent cut bank — the elevation that confines the river’s bed — measured at the average or mean level when the water reaches and washes that bank without overflowing it. The Court relied on historical treaty language, past decisions about other river boundaries, and the physical description of the Red River valley to reject both extremes: not the low-water mark urged by Texas and not the far bluffs urged by Oklahoma and the United States.

Real world impact

Practically, the ruling fixes the line along that cut bank where it existed in 1821 subject to the usual rules about gradual changes from erosion and accretion and sudden changes from avulsion. The Court resolved several local island and cut-off disputes (rejecting some Texas claims and accepting one avulsion claim) and ordered commissioners to survey and mark the boundary. This affects state jurisdiction, land titles, and future surveys in the river valley.

Dissents or concurrances

Justice McReynolds dissented, arguing the treaty should be read to fix the boundary at the low-water mark so that inhabitants would retain easier access to the river’s waters; he favored a different practical result.