How about saving the Rio in Big Bend? I have been reading in TRPA Facebook page about a proposal to extend the fence out that way. Not that is needed because there is only 2 ways out of Big Bend and both have checkpoints 100 miles away before anyway of connecting to a major road. Santa Elena Canyon is 1,500 feet high so should be considered a wall. There are even fewer roads into Mexico so not really a path for migrants.