The term 'Glen Canyon' is associated with the Glen Canyon DAM, a concrete arch-gravity DAM on the Colorado River in northern Arizona, United States. The DAM was built between 1956 and 1966 and impounds Lake Powell, one of the largest man-made reservoirs in the United States. The DAM's primary purpose is to provide hydroelectric power and to store water for use in the Upper Basin states of the Colorado River Compact. The three-letter solution for this crossword is 'DAM'.