In 1963, Glen Canyon Dam was completed, flooding 186 miles of the Colorado River and a spectacular region that had been proposed as a National Park before WWII. The 125 major side canyons of Glen Canyon, comprising the biological heart of the Colorado River, was flooded as Powell Reservoir backed up over the next 17 years. David Brower summed up the feelings of many when he called the loss of Glen Canyon, "America's most regretted environmental mistake."
Glen Canyon Institute (GCI) was founded in 1996 as a charitable 501(c)3 nonprofit organization with the mission of restoring a healthy Colorado River through Glen Canyon. Leading the movement to restore this uniquely beautiful place, Glen Canyon Institute immediately began work to conduct scientific studies on the impacts of Glen Canyon Dam, and compiled the results in the Citizen's Environmental Assessment (CEA), which was released in 2001.