PABLO, Mont. – The Confederated Salish and Kootenai Tribes have drafted legislation for returning the National Bison Range to federal trust ownership.

The agreement comes after a lawsuit was filed challenging the transfer of the lands and control of the bison, saying more research is needed.

A Bison Range Working Group has been formed to work on the project. The tribes are asking Montana’s congressional delegation to introduce a bill, but there has been no agreement on the legislation, the Missoulian reported.

The U.S. Fish and Wildlife Service told tribal chairman Vernon Finley in February that it would support a transfer, but a lawsuit has been filed that says more research is needed.

One issue hanging over the pending agreement is funding.

“The Fish and Wildlife Service made clear that, once it leaves the National Refuge System, there would be no funding coming to operate it,” tribal spokesman Rob McDonald told the Missoulian. “All operating costs would fall upon the tribes.”

The proposed bill calls for the secretary of the Interior to transfer funds, property, equipment and other resources to help with costs for two years.

The refuge was established in 1908, when bison were in threat of extinction.

Land on the Flathead Indian Reservation was removed from tribal control without the tribe’s consent.

Supporters say the animals are no longer in danger of extinction.