CNN iReport

     In Germany, 96 miles of concrete divided a population for 28 years.  It cost 136 people their lives, and when it fell, millions cheered the demise of a symbol of repression.

     Only five years later, construction would begin on another wall, this one between the United States and Mexico.  Since its inception, 5,600 people have perished trying to cross what is now more than 630 miles of steel, concrete, and vast, unforgiving desert.

     Though a graveyard for lost border crossers, the deserts of the border Southwest are an Eden for an array of wildlife species.  Much of their habitat is now blocked by new, hastily-constructed border walls, many of which seem better suited to blocking wildlife than people.

     Such is the case in Arizona's San Pedro Riparian National Conservation Area.  A United Nations World Heritage Natural Area, this biologically diverse and archeaologically rich gem lies along one of the last remaining free-flowing rivers in the American Southwest.  Hundreds of species of birds, as well as dozens of reptile and mammal species call the San Pedro home, or stop there on their annual migration routes.  Photos show these routes being impeded by the border wall, with animals large and small detoured, stranded, even killed, by the section of massive new border wall that now slices across the Conservation Area.

     For more information on the border wall's environmental impacts, including a Google Earth powered border tour, check out www.sierraclub.org/borderlands or find the Sierra Club Borderlands Campaign on facebook.