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Glen Canyon
The Colorado River canyon mostly drowned beneath Lake Powell
Few American landscapes have been mourned like Glen Canyon. Stretching about 170 miles (273 km) along the Colorado River through southern Utah into northern Arizona, it was a maze of sandstone alcoves, side canyons and hanging gardens that John Wesley Powell's 1869 expedition named for its sheltered glens. Places such as Music Temple and Cathedral in the Desert drew river runners for decades. Then came Glen Canyon Dam, built between 1956 and 1966. Its gates closed in January 1963, and Lake Powell rose to full pool in 1980, flooding most of the canyon under hundreds of feet of water.
The loss became a founding grief of the modern environmental movement. The Sierra Club published The Place No One Knew in 1963, and David Brower and Edward Abbey wrote of the canyon for the rest of their lives. The canyon and reservoir now lie within the 1.25-million-acre Glen Canyon National Recreation Area. Below the dam, a 15-mile stretch of the original gorge still flows to Lees Ferry. Upstream, two decades of drought have dropped Lake Powell to less than a quarter full in 2026, and long-submerged side canyons and arches are reemerging from the mud.