Glen Canyon is a natural canyon in the Vermilion Cliffs area of southeastern and south-central Utah and north-central Arizona in the United States. Like the Grand Canyon to the south, Glen Canyon is part of the immense system of canyons carved by the Colorado River and its tributaries.
In 1963, a reservoir, Lake Powell, was created by the construction of the Glen Canyon Dam, flooding much of Glen Canyon beneath water hundreds of feet in depth. Lake Powell was the result of negotiations over the controversial damming of the Green River within Dinosaur National Monument, a project which was abandoned in favor of the Glen Canyon Dam. The dam remains a central issue for modern environmentalist movements. Beginning in the late 1990s, the Sierra Club and other organizations renewed the call to dismantle the dam and drain Lake Powell in Lower Glen Canyon.
Today, Glen Canyon and Lake Powell are managed by the U.S. Department of the Interior within Glen Canyon National Recreation Area.