Phoenix • U.S. Interior Secretary Sally Jewell and other officials will mark the 50th anniversary of Lake Powell's Glen Canyon Dam, a structure that helped usher in a new era in the Southwest.

The Glen Canyon Dam, situated near the Arizona-Utah border, generates power and water for approximately six states in a region prone to drought.

The dam is a key part of the Colorado River Storage Project but has also been a source of controversy.

Since the 1960s, the structure in Page, Arizona, has blocked 90 percent of the sediment from the river from flowing downstream, turning the once muddy and warm river into a cool, clear environment that helped speed the spread of extinction of fish species and endangered others.

It also has impacted beach recreation and archaeological sites.