EMIGRANT — U.S. Interior Secretary Ryan Zinke ordered a 20-year ban on new mining claims on a swath of public land in the mountains north of Yellowstone National Park on Monday, a move that comes three years after concerns were first raised that two gold mining proposals would mar the northern gateway to the nation’s first national park.

At an outdoor ceremony with a cloud-covered Emigrant Peak behind him, Zinke finalized an order withdrawing mineral rights from 30,000 acres of federal lands in the Absaroka Mountains near where two mining companies want to drill for gold.

He was joined by local business owners and conservationists who led the charge against the two proposals because they worried mining could harm wildlife, water quality and the region’s tourism-based economy.

“I’m a pro-mining guy,” Zinke said. “But there’s places to mine and places not to mine.”

The prohibition extends a two-year ban the Obama administration ordered in 2016, which was set to expire in November. A 20-year ban is the longest term Zinke could order, and his decision comes weeks after the U.S. Forest Service recommended rights be withdrawn for that length of time.

The withdrawal area is split between land near Emigrant Peak and near the town of Jardine, which is along the border of Yellowstone National Park. Two separate mining companies proposed drilling in the two locations in 2015 — Crevice Mining Group on Crevice Mountain near Jardine, and Lucky Minerals in Emigrant Gulch.

Locals and conservationists opposed the two companies almost immediately, raising concerns that the projects could sully the Paradise Valley. They celebrated Monday’s announcement as a major step forward in the battle against the two companies, which has now lasted more than three years.

“This has truly been a ground-up, grassroots effort,” said Michelle Uberuaga, executive director of the Park County Environmental Council.

The withdrawal doesn’t affect existing claims and doesn’t directly affect drilling plans on private land, but supporters believe it will hamper any expansion plans the companies might have.

Zinke, who has opposed the two projects since his time as Montana’s lone congressman, said he doesn’t believe the companies can mine profitably with federal rights being withdrawn.

“I don’t see a path forward,” Zinke said.

The ban won’t halt all mining activity. Crevice Mining Group, the company that wants to mine near Jardine, has permission from the state to mine its private land claims as long as its surface disturbance doesn’t exceed 5 acres.

Lucky Minerals plans to begin drilling on private land near Emigrant Gulch next year. The Montana Department of Environmental Quality approved the company’s plans last year, but work hasn’t begun. The Greater Yellowstone Coalition and the Park County Environmental Council have sued to invalidate DEQ’s decision to approve the work.

John Mears, president of Lucky Minerals, spent much of Monday standing outside the lodge that hosted the signing event. He held a large sign asking Zinke why he wouldn’t meet with him. Mears, who has worked for Lucky Minerals since early August, said he has tried to set meetings with Zinke and members of Montana’s congressional delegation but has been unsuccessful.

“It’s just frustrating to not be able to be heard,” Mears said.

He is disappointed with the withdrawal, which he called a “land grab.” He said the decision will make it impossible to expand his project but won’t kill it. The company has raised roughly $5 million from investors and they’ve had crews working on their property this year.

Lucky Minerals has claims within the withdrawal area, and Mears said the company is waiting for the U.S. Forest Service to determine whether those claims will be subject to the withdrawal.

If the ban is made permanent by Congress, he said they’ll consider suing the government for taking their property without proper compensation.

“It’s not over for us,” Mears said. “We will fight.”

Supporters of the ban will continue to push for the ban to become permanent, which can only be done by Congress. The entire Montana delegation supports legislation that would make it permanent, and each of the three members issued statements on Monday thanking the Interior Department for the 20-year stoppage.

Montana’s Democratic U.S. Sen. Jon Tester and Republican Rep. Greg Gianforte have each introduced bills to make the ban permanent. The House Natural Resources Committee advanced Gianforte’s bill in late September. Tester’s bill cleared the Senate Energy and Natural Resources Committee last week with the help of Montana’s Republican Sen. Steve Daines.

Michael Wright can be reached at mwright@dailychronicle.com or at 406-582-2638. Follow him on Twitter @mj_wright1.