Along the Rio Grande, Scenes of a Tense Border

The Rio Grande
The river wends its way past Taos, New Mexico. Nelson observes that the Rio Grande starts in the mountains, where the water is crystal clear, then travels 1800 miles through three U.S. states. "Following its path," he writes, "one travels through a landscape that reflects the deep-seated divides currently underpinning the nation's political landscape. By the time the water empties into the Gulf of Mexico, it is polluted, depleted and muddied, like the region's politics."

• Arizona's Great Divide