Unlike the pipeline project at Standing Rock, however, Peabody’s mine plan has the backing of the official tribal governments because the original mine is one of the few sources of jobs and revenue on the impoverished reservations. Peabody has paid about $50 million per year to the Navajo and Hopi tribes since 1987, according to a federal report released in 2012, because the mine was built on tribal land.

But several powerful Navajo nongovernmental organizations, at odds with their leaders, have joined with the Sierra Club to try to curb the mine expansion, arguing that the mine harms air and water quality and that Peabody’s initial plan did not include enough protections for so-called cultural resources like graves. While they acknowledge that they cannot stop the mine project, they at least want Peabody and the government to protect ceremonial sites, ruins and graves in the expanding mine’s path.

To that end, these groups have brought a lawsuit that has forced the government to undertake a Preservation Act study to identify burial grounds and sites of archaeological importance. For projects on or near tribal land, the government must consult with tribes.

The problem, however, say tribal activists and preservation law experts, is that the permitting system is set up in such a way that it usually favors the project proponents while giving short shrift to tribal concerns. Even when “tribal consultation does happen, it’s often not in the spirit of the law,” said Anne Mariah Tapp, a lawyer who works on similar cases for other tribes.