The chairman on the Hopi tribe says he's profoundly disappointed about a federal recommendation to lift the 20-year ban on uranium mining on public land outside Grand Canyon National Park.
Herman Honanie says the thought of opening the area up to uranium mining is indefensible.
He says the government should clean up and reclaim existing contaminated sites before it promotes renewed uranium mining.
The U.S. Forest Service has proposed the change in response to President Donald Trump's executive order for federal agencies to eliminate restrictions on energy production.
The Trump administration has moved to unravel former President Barack Obama's environmental regulations aimed at curbing climate change.
Conservationists are decrying the Forest Service's move, saying past uranium mining in the region has polluted soils, washes, aquifers and drinking water.