how long would the border wall need to be?
Great Wall of Mexico US-Mexico Border Fence / Secure Fence He also opined that the wall should be see-through, ie, a fence, not a wall. Border patrol agents needed to be able to spot threats on the other side and avoid any âlarge sacks of drugsâ thrown over the top. Executive Order 13767 directed the Government to build a border wall with Mexico. The entire U.S.-Mexico border covers 3,200 kilometers, over a variety of terrain, from California, through Arizona and New Mexico and ending in southern Texas.