Attorneys for the Public Employees for Environmental Responsibility filed a lawsuit this week over a potential transfer of the National Bison Range to the Salish and Kootenai tribes in Montana.

"We are claiming that this is a federal action that under the National Environmental Policy Act, requires an environmental impact statement before any such proposal is made to Congress," PEER Senior Counsel Paula Dinerstein said. "We are also challenging the fact that the National Bison Range does not have a comprehensive conservation plan, which is required under federal law."

The Associated Press reports that federal officials "failed to conduct an environmental review before deciding to support the transfer of the bison range near Moiese to the Confederated Salish and Kootenai Tribes."

Dinerstein said the National Environmental Policy Act requires that environmental impact statements be done not only for major federal projects affecting the environment, but also for proposals for legislation.

"There has never been a refuge taken out of the federal refuge system before, and this is one of the premiere refuges," Dinerstein said. "As far as we can tell, there would be no guarantee in the legislation that it would be managed the same way that the federal government is managing it as a refuge for all Americans, and to protect the bison and the other wildlife that are there. It would be left up to the tribes."

The AP reports wildlife service spokeswoman Anna Munoz said under the proposal, the range would continue to be managed to maintain a herd of 300 to 400 bison. Munoz is also a proponent of the transfer.

Dinerstein said the government has 60 days to respond.