Conservations are becoming increasingly worried as the Trump Administration sends out signals that it is considering lifting the ban on uranium mining around the Grand Canyon.

The government’s decision to put uranium on a list of materials crucial to national security, ensuring that there is always a “sufficient supply” of the resource, as well as a recent recommendation by the Commerce Department to increase uranium mining, is causing many environmentalists to fear that Trump will open up mining in the protected area.

An additional sign that the administration may allow harvesting of uranium in the region may come soon, as President Donald Trump decides whether or not to implement a requirement that 25% of uranium purchased by the government be domestically produced. Such a requirement would greatly boost the power and economic demand of uranium found in the U.S. allowing local companies such as Energy Fuels and Ur-Energy to sell more uranium at a higher price. Currently, the United States imports most of the component from allies such as Canada and Australia.

Since 2012 the lands surrounding the Grand Canyon have been sheltered from mining by an Obama-era moratorium, but as the Trump administration shows increased support for the mining industry, many conservationists worry that his next step will be to remove land protections. Some political strategists believe that Trump may open up mining around the national landmark as a way to help his 2020 campaign. Since Arizona is a battleground state, the president could increase his popularity there if he created more jobs by allowing companies to mine the state’s resources.

Democrats are, unsurprisingly, against such a measure. The House has moved to expand the current moratorium for another 100 years, citing environmental degradation and health concerns. “The people of Arizona know the facts — that uranium mining is a threat to our precious water resources, to our tribal communities, and to one of our greatest national treasures,” remarked the Chairman of the House Natural Resources Committee Raúl Grijalva (D-Arizona).