The U.S. Supreme Court won't review an Obama-era action that put land around the Grand Canyon off-limits to new mining claims, ending the legal battle as environmentalists keep a close eye on actions by the Trump administration that they fear could lead to more access for the mining industry.

The Obama administration put about 1,562 square miles (4,045 square kilometers) outside the boundaries of the national park off-limits to new hard rock mining claims until 2032. The 20-year ban was meant to slow a flurry of mining claims over concern that the Colorado River — a major water source serving 30 million people — could become contaminated and to allow for scientific studies.

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 on Monday declined the request, leaving the ban in place.

"Clearly, we're disappointed," said Ashley Burke, a spokeswoman for the National Mining Association. "There continues to be great risk to our domestic supply chain thanks to unwarranted withdrawals like this." Burke said the association will continue advocating for land access. The American Exploration and Mining Association also challenged the ban. Environmentalists hailed the court's decision but are worried the ban could be undone administratively.

The Supreme Court is refusing to hear an appeal from a California billionaire who doesn't want to open a road on his property so that the public can access a beach.

The justices said Monday that they will not take up Vinod Khosla's appeal of a California appeals court decision. The case had the potential to upend California's longstanding efforts to keep beaches open to the public.

Khosla bought the property in the San Francisco Bay Area for $32.5 million in 2008 and later blocked the public from accessing it. That prompted a lawsuit by the nonprofit Surfrider Foundation.

A state appeals court ruled last year that Khosla needed to apply for a coastal development permit before denying public access.

Khosla — a venture capitalist who co-founded the Silicon Valley technology company, Sun Microsystems — closed a gate, put up a no-access sign and painted over a billboard at the entrance to the property that had advertised access to the beach, according to the appellate ruling.

The secluded beach south of Half Moon Bay, about 35 miles (56 kilometers) south of San Francisco, is only accessible by a road that goes over Khosla's land.

The previous owners of the property allowed public access to the beach for a fee. But Khosla's attorneys say the cost to maintain the beach and other facilities far exceeded revenue from the fees.

The government cannot demand that people keep their private property open to the public without paying them to do so, Khosla's attorneys said in their appeal to the U.S. Supreme Court.

The state appeals court ruling would "throw private property rights in California into disarray," the appeal argued, saying other property owners along California's coast would prefer to exclude the public.

The Surfrider Foundation said Khosla's appeal to the U.S. Supreme Court was premature because he had not yet applied for a permit and received a decision from the state.