The Carey Act and the Magic Valley
Near Twin Falls, Idaho
The land around Twin Falls was, in eighteen ninety, a sagebrush desert. The soil was fertile enough, volcanic ash over deep loam, but it received only nine inches of rain per year. Without water, nothing grew. The Snake River ran below in its canyon, five hundred feet down, unreachable by gravity without engineering on an enormous scale.
Congress had passed the Carey Act in eighteen ninety-four, a law offering western states up to a million acres of federal desert land if they could attract private capital to irrigate it. Idaho was the first state to successfully use the act. In nineteen hundred, a developer named Ira Perrine partnered with a group of investors, including Frank Buhl, who called themselves the Twin Falls Land and Water Company and proposed something audacious: a diversion dam on the Snake at Milner, fourteen miles upstream, that would back water into a canal system and push it across the canyon rim onto the desert above.
The Milner Dam was completed in nineteen oh five, an earthen structure stretching more than two thousand feet across the river. The main canal ran eighty-four miles. Within three years, more than two hundred thousand acres of what had been desert were under cultivation, producing potatoes, sugar beets, and dairy. The town of Twin Falls began to be platted in nineteen oh three and nineteen oh four, before the dam even finished, and lots were sold by the thousands to settlers who had never seen the place.
The region adopted the name Magic Valley, partly marketing, partly genuine astonishment at the transformation. By nineteen ten, what had been empty sagebrush flat was one of Idaho's most productive agricultural zones. The human cost of that transformation went largely unacknowledged at the time: the diversion eliminated the salmon runs that had sustained the Shoshone-Bannock for generations, and the influx of settlers pushed remaining tribal members off the land they had occupied since before written history.
Milner Dam stands today, still diverting the Snake, still feeding the canals. The Magic Valley produces a significant share of the nation's trout, potatoes, and dairy, all of it dependent on the water that Perrine and his partners figured out how to move uphill by gravity more than a century ago.
