Plum Creek Timber Co. announced Tuesday that by year end, the Seattle-based company will close a deal to purchase 48,500 acres northwest of Greenville from Hancock Timber Resource Group.

In Maine, where massive land deals are becoming a regular occurrence, the sale is newsworthy only in that it will help to make Plum Creek, with just shy of a million acres, the third-largest private landowner in the state.

But the map that accompanied Tuesday’s announcement was anything but business as usual. With blocks of color, Plum Creek had laid out an unheard of 30-year plan covering 380,000 acres, which, including the new property, composes about 40 percent of all its holdings in Maine.

The plan either shows the most ambitious development project in the state’s recent history or an entirely new way of thinking about forest management.

With 5,000 acres proposed for housing development, two resorts (one near the town of Rockwood and the other on Moosehead Lake’s Lily Bay), and an area zoned for industry (possibly a mill), the plan is a far cry from the sort of working forest conservation easements that surround the Plum Creek land.

But with nearly all of the acreage to remain working forest and large parcels marked for possible conservation sales to the state – all bisected by a 74-mile snowmobile trail and 45 miles of trails set aside for summer hiking and winter skiing – the project doesn’t exactly scream sprawl either.

“This is big,” Maine conservation Commissioner Pat McGowan said Tuesday. “A lot of people have been waiting for Plum Creek to come forward [with a plan] for a long time.”

Gov. John Baldacci too, finds the project intriguing, said spokesman Lee Umphrey. But while the plan’s balance of conservation, economic development and recreation seems to fit the administration’s vision for the north woods, both McGowan and Baldacci said Tuesday they need more details before deciding whether to endorse the proposal.

Profitable companies have always planned for the long term, designing harvesting regimens and road construction around the potential future sites of vacation home developments or conservation lands. Large conservation projects like the Pingree easement in northern and western Maine have “carved out” lands suited for development while placing most of their acreage under easement.

But rarely, if ever, are decades’ worth of development dreams made public, exposing the company to the rancor of those who cast a critical eye on development in the north woods.

“It’s all about certainty,” explained Rick Holley, president and chief executive officer of Plum Creek, who traveled from his Seattle office for a whirlwind tour of Maine to promote the plan this week.

If approved by the state’s Land Use Regulation Commission – the body that oversees development in Maine’s unorganized territories – Plum Creek could confidently invest in its planned developments, knowing that refusal of individual projects would be unlikely.

Plum Creek downplayed the role of development on the 380,000 acres Tuesday, pointing out that 95 percent of its acreage would remain in use for timber or be protected under some kind of conservation scheme. The proposed business, residential and recreational developments would make up just 5 percent of the total acreage, the company said.

With Maine’s forests nearly recovered from the spruce budworm epidemic of the 1980s, the future is bright for paper and timber businesses, and convincing a company to bring in a mill or other forestry-related industry to the Greenville area shouldn’t be a problem, said James Lehner, who manages Plum Creek’s Northeast operations from his Fairfield office.

“Grow it, and they will come,” he said Tuesday, referring to the parcel set aside for industrial development. “The industry is going to be located where the timber is.”

John Simko, town manager of Greenville, supports the project, hoping it can help bring some of that economic growth to his community, which has always depended on forest resources for its livelihood.

But just three years ago, the Plum Creek headquarters stated its intention to develop more of its land, as profits shifted from timber to housing and recreation. The company is not an old-school firm, growing trees for paper or lumber. Rather, it has been incorporated as a real estate trust with the goal of using forestland in many different ways to turn a regular profit. Last year, the company reported a net income of $192 million, with total revenues in excess of $1.1 billion.

“They’re in the business to make money,” said Jym St. Pierre of RESTORE: the North Woods. “Cutting trees, growing houses, selling land for conservation – whatever it takes.”

Much of the Plum Creek land included in the plan released Tuesday falls within the proposed boundary lines for the North Woods National Park advanced by RESTORE. And the property, owned by timber companies for decades, is some of the wildest in the state, beloved by Appalachian Trail hikers as well as local hunters and fishermen.

The Appalachian Mountain Club supports the plan, as does the Sportsman’s Alliance of Maine and the Maine Snowmobile Association – all of which would gain guaranteed recreational access.

However, Plum Creek is making no promises beyond the 30-year mark, saying Tuesday that the company and the state would have to respond to the state of the forest industry at that time. And it’s unclear whether this sort of voluntary resource plan, even one officially accepted by the state, would prevent Plum Creek from changing its policies before the 30 years are up. A plan could be written to allow the company loopholes, and Plum Creek’s proposal will have to be read closely to determine the strength of its conservation provisions, LURC Director Catherine Carroll explained Tuesday.

Though disturbed by the idea of development, Karen Woodsum of the Sierra Club’s Maine chapter was particularly pleased that Plum Creek proposed protecting 37,000 acres of the “hundred-mile wilderness” along the Appalachian Trail in the conservation parcel being offered to the state.

McGowan added Tuesday that several areas identified by the company as possible conservation sales have the ecological value that his department looks for in new acquisitions. The Roach ponds and the No. 5 bog, near Attean Pond, in particular, have long been on the state’s wish list. But no conservation can happen until the Land for Maine’s Future grant program is funded, he said.

Environmentalists, who have seen only the bare details released Tuesday, were cautiously optimistic, praising Plum Creek for incorporating conservation into its development but raising concerns about the balance between housing, wilderness and multiuse recreation lands.

It’s all about balancing the quantity and quality of lands designated for development or conservation, they said. Plum Creek declined to provide details about specific development proposals Tuesday.

“I’ll give them credit for trying something new here,” St. Pierre said. “It’s not a national park, that’s for sure, but we’re going to have to look at how good the mix is.”

Cathy Johnson of the Natural Resources Council of Maine estimated that as many as 800 new home or camp lots could fit into the 5,000 acres allotted in Plum Creek’s plan – many times larger than the biggest development proposal ever considered by LURC.

And the company isn’t talking about its plans for the remaining 60 percent of Plum Creek’s holdings in Maine, which total about a half-million acres, she said.

“This is a turning point in the history of Maine’s north woods,” Johnson said. “This scale of development could change the character of the Moosehead region forever.”

LURC has not yet received an official request to consider Plum Creek’s plan, but the matter could be on the board’s agenda as soon as January, with the requisite public hearing occurring before spring.