There's an old uranium mine on rancher Larry Gordy's grazing land near Cameron, Ariz. Like hundreds of other abandoned mines in the Navajo Nation, the United States' largest Indian reservation, it looks as if it might still be in use—tailings, or waste products of uranium processing, are still piled everywhere, and the land isn't fenced off. "It looks like Mars," said Marsha Monestersky, program director of Forgotten People, an advocacy organization for the western region of the vast Navajo Nation, which covers 27,000 square miles in Arizona, Utah and New Mexico.
The U.S. Environmental Protection Agency is currently embroiled in a massive effort to assess 520 open abandoned uranium mines all over the vast reservation. (Forgotten People says there are even more mines on Navajo land: about 1,300.) Earlier this month, the cleanup got a boost from a bankruptcy settlement with Oklahoma City-based chemical company Tronox Inc., which will give federal and Navajo Nation officials $14.5 million to address the reservation's uranium contamination.
http://www.scientificamerican.com/article.cfm?id=abandoned-uranium-mines-a