This brief article from the Washington Post outlines why a border fence is impractical and likely to fail as a deterrent for undocumented immigrants. The reasons? The border is lined with a number of dry creek beds along the Arizona-Sonora border, which are prone to flash floods during the rainy season. The barrier would also have to traverse the Huachuca Mountains and other craggy ranges west of Nogales, Arizona, where the the ravines and bluffs are inaccessible to cars and trucks. The fence is also likely to simply push immigrants and smugglers to other crossing points that will have less scrutiny.