Massive environmental destruction promised by the Resolution Copper Mining project at Oak Flat campground near Superior in theory could be halted by findings from an upcoming study.

The federal process of producing an environmental impact statement on the project can't stop the planned mine directly, anti-mining activists admit. But depending on what the review concludes, it could be used as key evidence for a possible law that would reverse the 2014 land swap that makes the project possible, they say.

Environmentalists and Native American groups have strongly opposed the project for more than 10 years but were dealt a blow in December 2014 with the unexpected land-swap deal by Republican Arizona U.S. senators John McCain and Jeff Flake, which trades 2,422 acres around Oak Flat for 5,344 the mining company owns elsewhere.

Last week, the U.S. Forest Service kicked off the study with the announcement of a public-comment period and dates for Q&A sessions around central Arizona (see below).

The EIS is expected to take several years to complete as officials scrutinize the mine's capacity for pollution, land degradation, and eradication of historic sites. Over the next few weeks, Forest Service officials will read through the comments and discuss the project with interested residents, all of whom will help determine the scope of the environmental analysis.

"The EIS is set up to disclose all the known effects of the project's plan

and develops a plan to mitigate Forest Service land impact," says Marie Sebrechts, spokeswoman for the U.S. Forest Service.

RCM, with majority ownership by Australia's Rio Tinto company, has acknowledged that the environmental impact will include a crater of sunken land more than a mile in diameter, plus the creation of a mountain of tailings that will be dumped in the desert. Outdoor enthusiasts have joined Native Americans in criticizing the project in an area that has been used extensively for decades by campers, hikers, bird-watchers and rock-climbers. This year, the third annual Queen Creek Boulder Comp will take place on April 2 and is expected to draw about 100 climbers.

Rio Tinto and mine supporters, including McCain and Democratic Congresswoman Ann Kirkpatrick, claim the project will be an economic boon to the state, digging out nearly two billion tons of ore and generating up to $60 billion in commercial activity over several decades.

Since the National Park Service put the site on the National Register of Historic Places earlier this month, the EIS will also study how, or if, mining activity would damage the place's historical significance.

Usually, the EIS process would allow the government to evaluate a project like this, then reject it based on the findings if the impact is too severe. But under the 2014 land-swap law, Rio Tinto gets title to land two months after the EIS is complete, whatever the EIS finds.

Still, it's not a done deal until that "dotted line" is signed, says Sandy Bahr, executive director of the Sierra Club's Grand Canyon Chapter.

She's confident the results of the EIS will "make it clear this swap is a bad deal for the American people."

The best hope for activists is a new law that unravels the land swap before it's finalized.

Last June, Arizona Congressman Raul Grijalva unveiled the "Save Oak Flat Act," which now has about 40 co-sponsors. It's been stalled by the GOP-dominated House, but the more time that goes by, the better the chances for that bill or something similar, says Curt Shannon, policy analyst for the Access Fund.

"If things get strung out four or six years, the makeup of Congress could change," Shannon says.

The EIS, being a mandatory bureaucratic government process, will build a long delay into the process that's welcomed by environmentalists like Shannon and Bahr.

The new historic designation will slow things down even more. Now, the EIS "has to take into account cultural issues that it would not have had to take into account otherwise," Shannon says.

But mining advocates cried foul over the sudden NPS designation. Republican Arizona Congressman Paul Gosar said earlier this month that the Obama administration's historic designation was "incompatible" with efforts to start mining operations.

Gosar also noted that Apache historian Dale Miles disputes the claim that Oak Flat is an important Native American site.

Andrew Taplin, RCM project director, said the company welcomes the EIS review "to identify potential environmental and cultural concerns so that they can be analyzed and mitigated ... As we move from project permitting to a mining operation, our pledge is continually improve our performance."

RMC expects to start mining in about five years, having already spent several years and more than a $1 billion in preparations.

Below: Information from the Forest Service on how to submit comments about the mine and on the upcoming open-house events.