PORTLAND, Maine — Two environmental groups blasted Cianbro Corp.’s east-west highway proposal on Monday, charging that the likely route would affect conservation sites and hurt the state’s economy by damaging its “brand” as a wild and natural place — allegations the project’s chief sponsor vehemently denied.

Jym St. Pierre, Maine director of Restore: The North Woods, and Jonathan Carter, director of Forest Ecology Network and a former Green Party candidate for governor, both said Monday that there are too many questions about the plan and public comment is too scarce.

“This proposal is a complete environmental nightmare,” said Carter.

Carter also suggested that the highway proposal actually was secondary to industry’s desire to have a potential resource and utilities corridor across the state with transmission lines carrying power and telecommunications and pipelines carrying tar sands gas, oil, water and other resources.

Peter Vigue, chairman and CEO of Pittsfield-based Cianbro Corp., strongly denied that on Monday.

“We have not had one conversation with anyone about any such thing — that is a fact,” said Vigue on Monday. “Their statements are totally unfounded.”

The 220-mile privately funded toll highway proposed by Vigue gained state funding for a $300,000 feasibility study in early April that is scheduled to be finished in January.

The $2 billion roadway would start in Calais, follow Stud Mill Road to Costigan, just north of Old Town, cross the Penobscot River, then head northwest to LaGrange, Milo, south of Dover-Foxcroft, Monson and The Forks before connecting to Route 27 and crossing the Canadian border into Quebec.

The initial plan has six interchanges in Maine, and from the border, it is only about 60 miles to Trans Canada Highway Route 10 near Sherbrooke — with connections to Buffalo, Detroit and other Midwest destinations — and to Trans Canada Highway Route 73 to Beauceville, located south of Quebec City.

Vigue has said that since the project is privately funded, eminent domain is not allowed and will not be used to acquire land for the project, which means the exact route is in flux until the land is under contract.

But St. Pierre on Monday displayed a large map showing what he believed would be the likely route across the state, pieced together from Vigue’s public presentations, and from a “confidential 2008 report prepared for Cianbro” that he and Carter said had been referenced by the Maine Department of Transportation request for proposals for the feasibility study.

“Depending on the precise route on the ground, it appears that the proposed east-west corridor would cross, come perilously close to, or be in the viewshed of more than five dozen significant conservation and recreation areas,” St. Pierre said. “My organization, Restore: The North Woods, has a direct stake in this issue because the proposed east-west corridor would cross part of our proposed Maine Woods National Park & National Preserve. It could also cross Atlantic salmon rivers and other wildlife habitats and ecosystems we have worked to protect.”

Vigue said the project would avoid any such areas, however.

“We are not going through any conservation areas whatsoever. We’re doing everything to avoid those and we recognize the importance of those conversation areas. We have no interest in going through any of those conversation areas — [St. Pierre and Carter] have totally misrepresented what we’re trying to accomplish,” he said.

The east-west highway proposal has proven contentious in public forums around the state, with residents demanding more information from Cianbro. Restore’s park proposal has in the past been fairly controversial as well, drawing criticism from residents of rural Maine.

St. Pierre said residents should be asking questions about the highway proposal, including regarding the environmental impact, whether the corridor would accelerate export of raw forest products, and whether the corridor would open up remote areas for grid-scale wind power and other energy products. He is also skeptical about Vigue’s claim that eminent domain would not be used to take land for the project.

“By making Maine just one more drive-through state, the east-west highway and corridor could destroy some of Maine’s best natural assets and put the state at a competitive disadvantage,” said St. Pierre. “It could further divide, rather than connect, the two Maines.”

Vigue said charges that the highway would destroy Maine’s tourism-based economy were unfounded. There are many tourism-related businesses in remote areas of Maine that are challenged to attract customers because of inadequate access, he said. He also said that existing manufacturing companies would benefit from better throughways to market, and noted Lincoln Paper & Tissue specifically.

“I stand by my record of enhancing and improving the economy in the state of Maine,” said Vigue.

The economy in the rural parts of the state has “been going in the wrong direction for the last 25 years, and there’s not a lot happening to try to correct it.”

“I recognize what the motives are for Jonathan Carter and Mr. St. Pierre, to make it one big park. I also understand their motive to block and stop any development in the state of Maine, specifically in those areas,” said Vigue. “If they’ve got a better idea on how to turn these things around and improve the economy in the northern part of the state I’d be more than happy to listen to them. But I have yet to see those two individuals do anything but try to stop and block activity in the north half of the state of Maine.”