by John Marshall Harlan

“ We perceive no reason to believe that Congress intended, either by the acts of 1820 and 1836 relating to Missouri, or the act admitting Nebraska into the Union, to alter the recognized rules of law which fix the rights of parties where a river changes its course by gradual, insensible accretions, or the rules that obtain in cases where, by what is called avulsion, the course of a river is materially and permanently changed. Missouri does not dispute the fact that when Nebraska was admitted into the Union the body of land described in the present record as Island Precinct was in Nebraska. ”

“ United States, and citing prior cases in which that rule had been recognized, said: 'It is equally well settled that where a stream which is a boundary, from any cause suddenly abandons its old and seeks a new bed, such change of channel works no change of boundary; and that the boundary remains as it was, in the center of the old channel, although no water may be flowing therein. This sudden and rapid change of channel is termed, in the law, avulsion. ”

“ These propositions, which are universally recognized as correct where the boundaries of private property touch on streams, are in like manner recognized where the boundaries between states or nations are, by prescription or treaty, found in running water. ”