The Supreme Court declined Monday to hear a case challenging the government’s ban on uranium mining in the Grand Canyon, a major blow to industry groups hoping to mine for the nuclear material.

The court said it would not hear the case brought by the National Mining Association and the American Exploration and Mining Association, which challenged the Interior Department’s ban as being based on an unconstitutional provision of the law.

The rejection leaves in place a December appeals court decision that upheld the ban.

In 2012, Obama administration Interior Secretary Ken Salazar instituted the ban, partly because the neighboring Havasupai Tribe relies on groundwater from the area to survive.

“The lands in and around the Grand Canyon have always been the homeland of the Havasupai People,” Muriel Coochwytewa, the tribe's chairwoman, said in a statement Monday.

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“Our ancestors lived and died amongst the sacred sites that cover this land. The mineral withdrawal is a necessary way to protect the land and the water that our people and our village depend upon, and we are grateful that the Supreme Court has agreed with the 9th Circuit’s conclusion ― that our lands and our people must be preserved.”

In March, the industry groups asked the court to review the ban, which prohibited uranium mining on public lands next to the national monument for 20 years.

While the Supreme Court's decision to not take the case leaves uranium mining companies no more avenues to challenge the ban in court, they are reportedly lobbying the Trump administration to support renewed mining in the U.S. for both economy and national security reasons.