Wouldn't this be a tremendous waste of resources -- to put a fence where there is no possibility of coming over the border? There is one thing some people are forgetting -- once a government project gets going, nothing stops it. The fence will be there forever. It will become a bottomless barrel of pork that will never end. Let's fence the most vulnerable and porous parts of the border first, then fill in the gaps where it is really needed. It seems to me that the Administration's approach to the fence is the rational one.
Any opening will be utilized. Nothing will prevent them, even rough terrain, from coming through the opening. Likely with assistance from the Mexican Government.