RENO, Nev. (AP) — Federal land managers say attempts by rural Nevada counties and others to block new U.S. policy intended to protect the greater sage grouse could ultimately force reconsideration of a recent decision to keep the bird off the list of endangered species.

Justice Department lawyers say it took an unprecedented effort by officials in 11 western states to persuade the Fish and Wildlife Service last month to reverse its conclusion five years earlier that a federal listing was "warranted."

They say the new finding was based on assumptions that added protections in the land planning amendments being challenged will be carried out to ensure the grouse no is longer threatened with extinction. They warn in new filings in federal court in Reno any injunction blocking the plans would "undermine" the listing decision.