Tonto National Forest: The Lake Behind the Dam Nobody Wanted

Roosevelt Lake sits in the desert northeast of Phoenix, a broad blue reservoir impounded behind a masonry dam that was, when it was completed in nineteen eleven, the largest masonry dam in the world. Theodore Roosevelt came to dedicate it in person, and the dam bears his name.

The Salt River Project, the federal irrigation program that funded the dam, was not universally welcomed. The Salado people had farmed this canyon system for centuries. The Yavapai and Apache families who lived in the Tonto Basin when the dam project was surveyed had been removed by federal force in the eighteen seventies, marched to the San Carlos Apache Reservation. When the survey teams arrived in the eighteen nineties, they found an emptied landscape. That emptying was not coincidental.

Tonto National Forest was established in nineteen oh five, two years after construction on Roosevelt Dam began. The forest today covers approximately three million acres of the Sonoran and Chihuahuan Desert transition, the largest national forest in Arizona and one of the largest in the continental United States. Its eastern half rises into the Mazatzal and Sierra Ancha mountain ranges, where Mogollon culture cliff dwellings have been documented for over a century.

Roosevelt Lake stores water that runs Phoenix. The farms of the Salt River Valley, the cities that grew from them, the suburbs that spread across the desert in every direction rely on water held behind Roosevelt and three downstream Salt River Project dams. The hydraulic system Theodore Roosevelt dedicated in nineteen eleven is still working. What it replaced, who it displaced, and what the desert looked like before the lake filled behind the dam are not visible from the water's surface.