Just a month or so after the Blackfeet successfully defended culturally valuable places along Montana’s Rocky Mountain Front from oil and gas development, they may have to do the same once again to preserve some mountains to the east.

On Thursday, the Assistant Secretary of the Interior for Land and Minerals Management proposed extending for another 20 years an order that locks up undeveloped mineral rights on almost 20,000 acres of public land in the Sweet Grass Hills of north central Montana.

The order, which would expire in April 2017 if not renewed, prevents any new mine development but has no effect on mining activities that were in place prior to 1997 when the order went into effect.

The Havre Office of the Bureau of Land Management is accepting public comment on the proposal until April 6 and will hold a public meeting at the Chester Senior Center, 618 E. Adams Ave., in Chester from 3 to 5 p.m. on Feb. 10.

The BLM has recommended extending the mining moratorium, which is good news for the northern tribes that consider the Sweet Grass Hills to be sacred. Those tribes include the Assiniboine, Blackfeet, Gros Ventre, Chippewa-Cree, Kootenai, and Salish.

More than two decades ago, the Blackfeet and Chippewa-Cree led a tribal effort to put the mining moratorium in place to protect the plants and rocks of the Sweet Grass Hills, which figure prominently in their story of creation.

In 1992, the Montana BLM Director Jim Baca designated 7,640 acres of the hills as an Area of Critical Environmental Concern. The designation confers some protection but did not limit the development of mineral rights.

When Lehmann and Associates partnered with Manhattan Minerals, Ltd, to form Mount Royal Joint Venture and filed that same year to develop a heap-leach gold mine in the hills, a group of ranchers, Blackfeet and conservationists came together to oppose the mine. They lobbied Montana Congressman Pat Williams, who asked that Interior Secretary Bruce Babbitt not only reject the mine application but suspend all new mineral rights in the Sweet Grass Hills.

The BLM did suspend mineral rights for the next two years while conducting an environmental impact study. That study found no evidence of harmful impact and the BLM prepared to issue the permit.

But the federal Advisory Council on Historic Preservation stepped in and found that the BLM had not consulted with the tribes. They recommended that the BLM redo the study.

During the second two-year study, BLM managers asked the northern tribes to identify sacred sites in the hills. Similar to those who spoke at the recent Advisory Council on Historic Preservation hearing on the Badger-Two Medicine, tribal leaders in the mid-90s said the entire extent of the Sweet Grass Hills was sacred, not just a few specific sites.

At the end of the second study, the BLM recommended withdrawing the mineral rights to “protect high value potential habitat for reintroduction of endangered peregrine falcons, areas of traditional religious importance to Native Americans, aquifers that currently provide the only potable water in the area, and seasonally important elk and deer habitat.”

Mount Royal Joint Venture responded by suing unsuccessfully several times, even though eight of its claims weren’t affected by the order. The only thing that prevented those claims from being developed was Montana’s citizen’s initiative to ban heap-leach mining passed in 1998.

Under the General Mining Law of 1872, suspension of mining rights can last only 20 years, after which the order must be renewed. Having to renew the Sweet Grass Hills order may open a window of opportunity for mining proponents.

That’s why some Blackfeet members have tried to put the Sweet Grass Hills on the U.S. Register of Historic Landmarks, which would give the area permanent protection. Efforts to contact Blackfeet Council members Harry Barnes and Joe McKay Friday were not successful.

BLM Havre Office spokeswoman Micah Lee said she didn’t know if any mining companies would oppose the extension but the BLM wants to hear from all interested parties.

Lee said the BLM would use the original EIS to inform its decision because little has changed in the Sweet Grass Hills in the past 20 years.

“By doing the extension, we’re just maintaining the status quo. We want to continue to protect the physical characteristics and the traditional spiritual importance of the area,” Lee said.