The red sandstone vistas in Utah’s Grand Staircase-Escalante National Monument may soon be criss-crossed with dumptrucks after a Canadian mining company announced plans to begin operations on land cut from federal protection by President Donald Trump.

Vancouver, British Columbia-based Glacier Lake Resources Inc. announced last week it had acquired a former copper mine on land formerly contained in one of the two national monuments that Trump shrunk last year, a move that was bitterly contested at the time by environmental and Native American groups.

“Surface exploration work will start this summer on the Colt Mesa property and drill permitting will be initiated shortly,” Saf Dhillon, president and chief executive officer of Glacier Lake Resources, said in a statement. The company plans to mine copper, cobalt and other minerals from an area about 200 acres (81 hectares) in size. The mine was last used in 1974, according to the company

Already, some fresh stakes and a new metal gate have appeared in the area known as Circle Cliffs, which is popular with hikers, climbers and other who come to explore the area’s scenic canyons, Colter Hoyt, a backcountry guide, said in a phone interview. Mining equipment for the project would reach the site via roads that travel through the park and nearby narrow canyons, he said.

Heather Swift, a spokeswoman for the Interior Department, said the monument had been “right-sized” to protect resources, while restoring much of the excluded lands to multiple use.

The department’s Bureau of Land Management office in Utah has yet to be contacted about the project, she added in an email. “BLM will be involved in reviewing any notice of intent or plan of operations, and will conduct any required environmental analysis consistent with its regulations and legal obligations.”

The Trump administration announced in late 2017 that it would reduce the 1.9-million-acre Grand Staircase-Escalante National Monument, created by President Bill Clinton in 1996, to about 1 million acres. It also announced it was shrinking the nearby 1.4-million-acre Bears Ears National Monument to about 220,000 acres. The land should be in the hands of the state instead of being under the federal government’s control, Trump said at the time. Many Utah Republicans have opposed the monuments as federal land grabs.

The decision followed an Interior Department review of millions of acres of land protected by national monuments, many of which contained reserves of oil, coal and other minerals off limits to development.

The move in Utah represents “the largest rollback of public lands protections in history,” said Dan Hartinger, national monuments campaign director for the Wilderness Society, one of several environmental groups suing to block the move.

Glacier Lake’s mine marks the first time a national monument has ever been opened to mining “as far as we can tell,” Hartinger said. “It’s incredibly concerning, but our view is mining claims are not valid,” he said.