Why would Texas be a problem?
>this reservation shall be construed and taken as extending to and including all public lands belonging to the United States which lie within sixty feet of the margin of such river or stream
Unless the Rio Grande is wider than 120 feet (60 ft on our side of the margin)..
was thinkin' water-wall.. but I guess sea-mines would work too as that river's gone to shit already as far as I'm aware.