WASHINGTON — The National Park Service put forward a draft plan Friday to release 20 to 30 new wolves on Isle Royale over a three-year period as a way to bolster a population on the remote Lake Superior island that has dwindled to just two and is in danger of vanishing altogether.

If the Park Service — which for more than a year has been looking at the fading Isle Royale wolf population and a moose herd that has swelled to 1,300 with its main predator in decline — follows through, it could quickly revive a closed ecosystem on the rugged 45-mile-long island protected from hunting and existing largely outside of human interference.

But it could also stir up concerns that the Park Service, in an attempt to address climate change and warmer winters that have in recent years reduced ice bridges to the island — in turn halting natural wolf migration from Canada — is setting a precedent that some environmental groups believe violates the federal Wilderness Act’s requirement that lands remain “untrammeled” by human intervention.

The draft plan recognized the dichotomy inherent in the Park Service's mission on Isle Royale, saying the proposed action will help to restore the natural order on the island by reintroducing an "apex predator" but noting it also results in "substantial impacts to (the island's) wilderness character overall because of the intentional manipulation of the ... environment." The proposal also calls for monitoring wolves placed on the island by radio collar.

“This is about more than wolves,” said Phyllis Green, superintendent of Isle Royale National Park, which takes up virtually all of the island located 55 miles across Lake Superior from the Upper Peninsula and is closed from November to April. “It’s about the entire park ecosystem and where it is heading in the future with changing conditions.”

She called it “a complex issue to address.”

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It's also one the Park Service has been accused of delaying far longer than was necessary.

For more than six years, researchers — especially those at Michigan Technological University in Houghton who have kept alive an annual report on the wolves and moose of Isle Royale and their interactions since the late 1950s — have been warning that the wolf pack, which included as many as 19 wolves in 2010, was on the decline, largely due to inbreeding and genetic deficiencies.

Those researchers and others, including those at the National Parks Conservation Association, which advocates for the parks, called for a reintroduction of wolves to bolster the herd, arguing that the annual study — which has produced insights into topics from arthritis to air pollution — is too valuable to lose and that a unthreatenedmoose herd that isn't threatened will do great ecological damage before dying out themselves.

As proposed, the preferred plan "would attempt to re-establish the wolf population in the shortest amount of time," the study said. But it specifically rejects any plan to add more wolves after five years, despite an alternative proposal, also under consideration, to add wolves more slowly over 20 years — a plan that while perhaps adding longer-term stability to the pack may not prevent the overall loss of the population in the nearer future and would lengthen the Park Service's direct intervention on what some believe should be untouched wilderness.

"What counts are paws on the ground," said Rolf Peterson, a research professor who has been part of the annual wolf survey done on the island by Michigan Tech for 46 years. But he said he wants to read the 183-page study put out by the Park Service more carefully before coming to a conclusion whether it is enough to protect the wolf population over the long term.

"Why do it once and then wash your hands of it? I want to read about that — I want to get into the weeds and see what they're really saying," he said.

In the most recent report last April, Michigan Tech’s researchers found evidence of only two gray wolves — believed to be a male and his daughter — as the last remaining members of the species on the island.

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Sen. Gary Peters, D-Mich., who has made a couple of trips to the remote island and last year, with his colleague Sen. Debbie Stabenow, D-Mich., had urged the Park Service to move more quickly in addressing concerns about the Isle Royale wolves, said he was pleased with the release of the draft plan.

"The wolves are a part of Isle Royale’s heritage, but I commend the Park Service for also recognizing the critical role of an apex predator to the entire Isle Royale ecosystem," he said, adding that he's committed to working with the scientific community, wilderness groups and others to ensure public input is taken into account as the plan moves forward.

Kevin Proescholdt, conservation director for the group Wilderness Watch in Minneapolis, noted his organization's objection to any interference and said it would continue to work with its members to get the Park Service to reconsider before making a final decision sometime next year.

"It's not a fait accompli," he said, adding that he was disappointed the Park Service "hasn't given a higher priority to the wilderness designation at Isle Royale" that argues against human manipulation of the natural forces there.

Christine Goepfert, senior program manager for the National Parks Conservation Association's Midwest Region, said reintroduction of wolves to Isle Royale is the "right call."

"In the absence of a predator, the moose population will continue to grow, which could devastate the island native vegetation, eliminating their food source as well as that of other species on the island. Through this analysis, the Park Service clearly illustrates the critical role wolves play in the park’s ecosystem," Goepfert said.

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Under the plan, the Park Service is releasing a draft Environmental Impact Statement, or EIS, that recognizes the “natural recovery of the (wolf) population is unlikely” and describes as its “preferred alternative” the plan to reintroduce 20 to 30 new wolves onto the island over the course of three years, though that could be stretched to five years if necessary.

With the issuance of the EIS, the Park Service will accept public comments on the plan until March 15. A final plan would then be issued sometime in mid to late 2017, with a “record of decision” formalizing approval coming after that. The draft EIS is open for public review and comment at http://parkplanning.nps.gov/isrowolves.

The draft EIS contains other potential alternatives as well that could be considered, including one in which no action would be taken and the other in which 6 to 15 wolves would be introduced on the island immediately with the potential for more over a 20-year period.

A third alternative would allow for continued monitoring but make no decision at this point whether to put more wolves on the island.

Park Service officials also expect to hold public meetings on the proposal in Minnesota, Wisconsin and Michigan, though no dates, times or locations have been finalized.

Contact Todd Spangler: 703-854-8947 or at tspangler@freepress.com. Follow him on Twitter at @tsspangler.