"The abandoned mine here, about 60 miles east of the Grand Canyon, joins the list of hundreds of such sites identified across the 27,000 square miles of Navajo territory in Arizona, Utah and New Mexico that are the legacy of shoddy mining practices and federal neglect. From the 1940s through the 1980s, the mines supplied critical materials to the nation’s nuclear weapons program."

http://www.nytimes.com/2012/04/01/us/ur ... l?src=recg