WASHINGTON (Reuters) - A U.S. federal appeals court on Tuesday upheld a lower-court ruling keeping a ban on uranium mining around the Grand Canyon, but also upheld a separate decision allowing a uranium mine nearby to open.

The decisions by the Ninth Circuit Court of Appeals in San Francisco, related to cases argued last December, come as Congress and the Trump administration seek to expand mineral extraction on public lands.

The U.S. Department of Agriculture last month proposed lifting the Obama-era mining ban on land near Grand Canyon National Park, an area of natural beauty in the western United States that also historically served a number of uranium mines.

Earlier this month, President Donald Trump reduced the size of the nearby Bears Ears National Monument in Utah by 85 percent.

That decision came after lobbying by the uranium mining industry, the Washington Post reported.

The National Mining Association had sought to upend the 20-year moratorium on new uranium mines near the Grand Canyon, which was put in place in 2012 by President Barack Obama’s administration. But the court ruled that the ban should stay in place.

“Withdrawal of the area from new mining claims for a limited period will permit more careful, longer-term study of the uncertain effects of uranium mining in the area and better-informed decision making in the future,” the court ruling said.

The Obama administration had imposed the ban amid concerns about threats to groundwater supplies, Native American cultural resources and scenic views in Grand Canyon National Park.

In the other case, the appeals court sided with the lower court to allow Energy Fuels’ Canyon Mine near the south rim of the Grand Canyon to open, despite a challenge by the Havasupai Tribe and environmental campaigners that the mine would threaten the watershed.

The House subcommittee on energy and mineral resources is set to hold a hearing on the previous administration’s restrictions on mining on Tuesday. In a hearing memo, the panel said withdrawal of lands from mining makes the United States too dependent on foreign countries for minerals.

Roger Clark, Program Director at the Grand Canyon Trust, said while the group welcomed the decision to uphold the ban it was disappointed that the court did not support the argument that a decades-old uranium mining permit for Canyon Mine needed to be updated.