The U.S. Supreme Court has denied review of a case centered on mining around the Grand Canyon.
The Obama administration put about 1 million acres near the national park off-limits to new mining claims in 2012. It was meant to slow a flurry of claims over concern that a major water source in the West could become contaminated.
The mining industry asked the Supreme Court in March to review the ban, saying it was based on an unconstitutional provision of federal law. The high court declined Monday.
A spokeswoman for the National Mining Association, Ashley Burke, says the ban is unwarranted and makes the U.S. even more dependent on imports.
Environmentalists hailed the high court's decision but are worried the Trump administration is working to end the ban administratively.