This Dam is one of two closely tied to the Grand Canyon. Glen Canyon lies 90 miles upstream from the Grand Canyon, and controls the water flow through that majestic formation. This is one reason the dam has been mired in controversy since its inception. It has disrupted the natural forces that shape the Grand Canyon. The Colorado River used to carry 50,000 tons of rocks, dirt, silt, and debris through this are each day. Now most of it is piling up in great silt plumes on the far end of Lake Powell, the body of water formed by Glen Canyon Dam. In addition, several species of local fish and other creatures were lost when the ecosystem changed. The construction of Glen Canyon Dam is commonly cited as one of the galvanizing events that helped forge the modern environmental movement. In the late 1990's, an experiment was tried to see if some of the natural balance could be restored. The dam was opened, and in essence, it flushed out the Grand Canyon. Scientists and ecologists were thrilled with the results, but because Glen Canyon Dam is so important for its water retention and power generating capacity, this is not likely to become a frequent event. In fact, it holds back 27,000,000 acre feet of water with its gentle curve, 710 feet tall from bedrock to rim. Lake Powell is now a magnet for visitors eager to enjoy its contrast between desert and water, and is known for is many houseboats

• 9,600,000 tons of concrete were used to build the dam -- enough to build a four-lane highway from to Phoenix, Arizona to Chicago, Illinois.
• The Glen Canyon bridge had to be built in order to bring construction supplies to the site. It is now a highway bridge.
• It took 17 years for Lake Powell to fill with water.