Sixty years ago Wallace Stegner published Beyond the Hundredth Meridian: John Wesley Powell and the Second Opening of the West. It’s a wonderful book about an extraordinary man, a one-armed Civil War veteran who became the first to navigate the Grand Canyon by boat, a journey so terrifying that three of his small crew took off at Separation Canyon, climbed the Colorado’s steep walls and were never seen again. Powell went on to a long career as an explorer and government agent. He was a staunch critic of the national obsession to overdevelop the west, arguing that its water resources couldn’t sustain the massive agriculture he foresaw. He pushed the novel idea of creating political boundaries based on natural watersheds. Stegner reprinted a rainfall map that shows why: east of the 100^th meridian the country has plenty of rain; west to the Rockies it is mostly desert. But governments and homesteaders ignored Powell’s warnings. Embracing the widely held and thoroughly debunked theory that “rain follows the plow,” they made the Great Plains bloom –nowhere more so than Nebraska, which became one of America’s most productive agricultural states. What it lacked in rainfall, it made up by finding itself atop the huge Ogallala aquifer and its seemingly endless water.

But Powell’s vision of a west of small farms, animal grazing and land protection has proved prescient. According to a recent study, Nebraska has become the driest state in America, all of it in the grip of severe drought, which caused last year’s wheat production to decline by 18%.