Glen Canyon Dam

What you're looking at, that massive concrete arc plugging a canyon seven hundred ten feet below the rim, nearly didn't exist. And the people most responsible for stopping it later wished they had.

In the early nineteen fifties, the Bureau of Reclamation wanted to dam the Colorado River at two places inside Dinosaur National Monument, including Echo Park Canyon. The Sierra Club, led by executive director David Brower, organized a national campaign that buried Congress in letters and turned the tide. By nineteen fifty-six, the Echo Park dam was dead. But the deal had a price: environmentalists agreed not to oppose a dam in Glen Canyon, a place most of them had never seen. Congress authorized the Colorado River Storage Project that same year, and construction on Glen Canyon Dam began in the fall of nineteen fifty-six.

What followed was one of the great ironies of the conservation movement. As Brower and others began floating Glen Canyon's rivers and side canyons in the years after nineteen fifty-six, they understood what they had traded away. Cathedral-scale alcoves, Anasazi ruins, arches, and side-slot canyons, a world that author Wallace Stegner later called the place no one knew, disappeared forever under the rising waters of Lake Powell. Brower called his agreement to sacrifice it the greatest sin he ever committed.

The dam itself is a feat of engineering difficult to absorb at close range. Five point four million cubic yards of concrete were poured over seven years, with workers running shifts around the clock. The first hydroelectric power reached Phoenix in nineteen sixty-four. On September twenty-second, nineteen sixty-six, Lady Bird Johnson dedicated the completed structure. Its eight turbines generate enough electricity for hundreds of thousands of homes across the Southwest.

But the dam's legacy remains contested. Lake Powell's sedimentation is slowly reducing its storage capacity. Drought across the Colorado Basin in the twenty-first century dropped the reservoir to historic lows, briefly exposing side canyons that had been submerged for decades. Scientists, river advocates, and water managers now debate what Brower spent his final years arguing: whether the time has come to drain the reservoir and restore Glen Canyon. The dam stands. The argument doesn't end.