A group opposed to killing wolves says it will circulate petitions to force a referendum on a new Michigan law allowing hunting of the once-protected predators.
Organizers of the group Keep Michigan Wolves Protected said Monday that it will seek to gather 225,000 signatures by late march to qualify for the November 2014 ballot.
The group is a coalition of animal welfare, conservation and Native American organizations.
The Legislature last month voted to classify gray wolves as a game species, and state officials are proceeding with plans for hunting them. Michigan has about 700 wolves.
The federal government in 2011 said wolves had recovered enough to be removed from the endangered species list. Since then, hunting has begun in Wisconsin, Minnesota, Idaho, Montana and Wyoming.