The National Park Service is weighing how to respond to dying wolves and a booming moose population on Isle Royale National Park. Wolves first walked across the ice of Lake Superior to Isle Royale in the late 1940s. Since then, their population has averaged around 20 animals. But now, due in part to genetic inbreeding, there are only three remaining. At the same time, the island's moose population has soared to 1,250.

The Park Service is considering a range of responses — including a solution that would add wolves now and another that would reintroduce them after the current animals die out.

Park Superintendent Phyllis Green said officials are also looking at options that involve relocating or killing some moose to protect vegetation.

"There are no options off the table," she said.

The public has until Aug. 29 to comment on the management plan and an environmental report the Park Service is developing.

Four open houses are scheduled for later this month, including one in Grand Portage, Minn. A final environmental impact statement isn't expected to be complete until late 2017.