Gray wolves in the greater Yellowstone area of the northern Rocky Mountains, which would have been fair game for hunters in three states as a result of a federal government decision in March, were again put under the protections of the Endangered Species Act by a judge in Montana on Friday.

The action by the judge, Donald W. Molloy of Federal District Court, took the form of a preliminary injunction and could be reversed. But Judge Molloy's language showed serious reservations about the Fish and Wildlife Service's decision to remove endangered species protections for the wolves.