Forest Service officials will allow exploratory drilling for copper and gold next to the Mount St. Helens National Volcanic Monument, including in an inventoried roadless area.

The decision, announced last week, drew swift rebuke from conservationists who say hard-rock mining is not appropriate so close to the national monument, and that it could threaten water quality in the nearby Green River.

Washington Sen. Maria Cantwell, the ranking member of the Senate Energy and Natural Resources Committee, also criticized the decision to allow exploratory drilling near Mount St. Helens.

“This mountain should be managed for current and future generations to enjoy, and I hope the Trump administration will cease their efforts to jeopardize that by allowing it to be explored for drilling,” Cantwell said in a statement.

Canadian-based Ascot USA could start drilling later this year if officials with the Bureau of Land Management, which oversees underground minerals on federal lands, also grant approval. BLM officials said they expect to issue their decision in coming weeks.

Ascot wants to drill about 63 holes at 21 drill sites about 12 miles northeast of Mount St. Helens on the Gifford Pinchot National Forest. Each hole would be about two to three inches in diameter.

The permit area covers 900 acres, much of it within the blast zone from the volcano’s 1980 eruption.

In issuing their decision, Forest Service officials emphasized that the permits address exploratory drilling only. They do not allow extractive mining to take place.

“Any potential future proposal would be subject to an entirely new and comprehensive environmental analysis and decision process to include multiple opportunities for the public and other interested parties to be informed, to consult, to comment on scoping and draft analyses, and to object to any draft decision,” Cowlitz Valley District Ranger Gar Abbas wrote in his final decision.

In 2012, conservationists filed a lawsuit to stop Ascot from conducting exploratory drilling in the area. Two years later, a U.S. District Court judge instructed the Forest Service to address flaws in its environmental analysis of the proposal.

The agency’s latest environmental review calls for precluding drilling next to the Green River and includes measures designed to lessen impacts on wildlife.