One of the nation’s largest environmental advocacy groups is opposing a proposed $2 billion superhighway that would link New Brunswick and Quebec through Maine, its director said Monday.

State club members feel the proposed highway would devastate Maine communities, environment and private property owners without any real benefit to Maine itself, said Karen Woodsum of the Sierra Club Maine Woods Campaign.

Sierra Club Maine will bring legal and economic resources from the club’s 1.4 million member national organization to battle the proposed highway on all levels, said Glen Brand, Sierra Club Maine director.

“Basically, we had people begging us to get involved with this,” Woodsum said Monday.

“What has been striking to us is that for the past two or three weeks, we have been lambasted with emails and phone calls from members, especially from those in the Dover-Foxcroft, Sangerville and Greenville areas,” she added. “That was really what sparked our interests in getting involved in a comprehensive campaign.”

Saying he saw a chance for improved commerce between Maine and Canada, Gov. Paul LePage in early April signed into law a bill setting aside $300,000 to study the feasibility of a privately funded highway connecting two Canadian provinces through Maine.

Republican Sen. Doug Thomas of Ripley, the bill’s chief sponsor, said it likely would be two years before the project, if it gets the go-ahead, would start.

The latest concept calls for a 220-mile highway extending from the Maine communities of Calais in the east to Coburn Gore at the border with Quebec. Private investors would bankroll the project, with estimated costs in the range of $2 billion, and maintain it with tolls paid by motorists.

Much of the traffic would be Canadian truckers moving their products from the Maritime Provinces to Quebec and Midwestern points, proponents say.

The LePage administration joined construction, pulp and paper and other business groups in supporting the bill. One of its biggest boosters is Peter Vigue, chairman of Cianbro Corp., a Maine-based construction company with operations around the country.

Club members join other local groups and residents in opposing the proposed highway.

Woodsum said the club’s frustration stems from it being denied information about the project and whom it would benefit.

Sierra Club members don’t oppose broadening Maine’s industrial potential but see many problems that the highway would create, including harm to waterways, water quality, critical habitat and threatened and endangered species; private property and eminent domain; local communities’ environment and economies; and public recreational lands, members said.

“There is a smarter way to move goods and generate economic activity through Maine: upgrading and using the existing Maine Montreal and Atlantic Railway rail line that travels east-west across Maine to Canada,” Band said in a statement released Monday.

The club will meet on May 17 to discuss assembling a study that would show how revitalizing the rail line would create the same economic benefits as a highway without the harm, Woodsum said.

The LePage administration’s support of about $10.5 million in repairs planned this summer for 233 miles of state-owned railroad tracks between Millinocket and Madawaska shows that improved rail service enjoys strong bipartisan support, Woodsum said.

The line’s previous owner and rail carrier, Montreal, Maine & Atlantic Railway, sought federal approval in February 2010 to abandon the tracks, citing losses of $4 million to $5 million annually. Maine taxpayers saved the rail line in June 2010 by approving $7 million in borrowing to buy the tracks after manufacturers who use the line said its collapse would doom Aroostook County’s economy. They were purchased by the state in 2010 for $19.1 million.

“That is very encouraging,” Woodsum said. “We actually plan to work on pulling together a thorough report of the economic benefits and feasibility of the east-west rail line.”

The Associated Press contributed to this report.