A public comment period has just ended, and the Obama administration is expected to decide the issue in the next few weeks. Toxicologist Steven Gilbert of Seattle, who weighed in on the proposal as director of the Institute of Neurotoxicology and Neurological Disorders, says Washington already has experience with uranium hazards from the Hanford nuclear plant site.
"Uranium is radioactive. You're exposed to radiation. One of the products is radon; you've probably heard of radon in people's basements. And then, you've got tailings - where's all the waste product going? Uranium is just the start of the process, and we haven't figured out what to do with the waste."
River trips are as popular on the Grand Canyon's Colorado River as they are in the Northwest. But Lynn Hamilton of Grand Canyon River Guides says runoff from existing uranium mines already has polluted several rivers, creeks and springs within the national park. She says Native Americans especially have been affected.
"It's really a deadly history. In fact, many Native Americans have died from drinking tainted water or using that water to sustain their livestock and crops when it's contaminated."
Grand Canyon draws 5 million visitors each year, Hamilton says, and supports about 12,000 full-time jobs.
The mining industry maintains that modern techniques prevent environmental damage, However, 63 members of Congress have sent a letter to Interior Secretary Ken Salazar, urging him to approve the 20-year moratorium. Only one, Rep. Jay Inslee, is from Washington.