In this April 26, 2021, file photo, heavy machinery is used to cut trees to widen an existing Central Maine Power power line corridor to make way for new utility poles near Bingham. Credit: Robert F. Bukaty / AP

Central Maine Power first proposed building a transmission line to Canada in 2017, and four years of controversy later, there are still hurdles ahead: legal challenges at the state and federal levels, a statewide ballot item set for November, unexpected technical issues to address.

But on Thursday, a federal court lifted an injunction that barred tree-clearing in one disputed segment.

And elsewhere on the corridor, trees are being cut and cleared, and poles are rising from the brush. Some observers say the $950 million project’s gathering momentum could make it unstoppable.

Up in Bald Mountain Township, miles into the timberlands east of Bingham, hard-hatted contractors maneuvered what look like giant Tonka toys across a 200-foot-wide swathe of cleared land.

Skidders and grappling hooks plucked and loaded downed trees that were recently cut for the new CMP corridor.

A dusty haze hanged in the air.

“I’m glad to have the sun and the dry conditions, I like seeing dust ’cause when there’s dust there’s no mud,” said Adam Desrosiers a project manager for CMP’s New England Clean Energy Connect.

The power line would take electricity from Canada’s Hydro-Quebec dam system into the regional grid, thanks to a contract with Massachusetts utilities.

Desrosiers and more than 400 others — CMP staff and contractors — have been working since before mud-season to clear trees, raise poles and string wire for the 141-mile-long, high-voltage line.

“This corridor was originally 125 feet wide, and we’ve added 75 feet of clearing on the western side. The forwarders and the excavators are bringing out the wood that’s been cut. As they come out, they bring timber mats back in with them. They’re building mat roads down there, you can see them, to cross the wetlands, and protect the ground,” he said, gesturing at their progress.

Poles in this segment, as with roughly two-thirds of the route, are going up alongside existing, smaller utility lines. Workers this year have already widened some 55 miles of that existing corridor.

Until Thursday, a key section where more than 50 miles of entirely new corridor would be cut from Jackman to The Forks, was off limits. Just before CMP was set to start cutting trees there, opponents won an injunction that put a U.S. Army Corps of Engineers permit for the work on hold.

“I mean it was a change that we didn’t expect at first, but we had this area that was ready to work, and we quickly pivoted and moved the crews into this area and got working. The last thing we wanted to do was lay off all these Maine workers that we had hired, and send them back home,” Desrosiers said.

But a federal appeals court lifted that injunction Thursday.

CMP could soon start ramping up its hires and start clearing trees in that disputed section.

Jobs for Mainers are a big part of the pitch CMP and allies like the Maine State Chamber of Commerce and the electrical workers union are making in their efforts to make sure the project survives the various challenges it still faces.

Opponents say even if CMP makes good on promises that most of the construction jobs will go to state residents, that work will be gone once the project is done. Meanwhile, the expanded corridor and the new cut to Jackman will bisect a unique woodland habitat, scarring it for decades and more, risking the health of many species, including rare native trout, pine martens and even mayflies.

“It’s horrific. It’s horrific. It shows an utter disregard for Maine,” said Elizabeth Caruso, a first selectman in Caratunk, a town on the corridor route, where many residents make their living in and around the Kennebec River.

CMP charges that opposition is being drummed up by fossil-fuel energy companies that could lose profits if the project goes through. And companies such as Calpine and NextEra have financed petition drives and lawsuits.

But it’s grassroots activists like Caruso and her husband — both certified Maine guides — providing the passion.

“They’re taking down our trees. They just don’t care,” Caruso saids.

And Caruso is quick to note that project profits will go to foreign entities — Canada’s Hydro-Quebec and Spain-based Iberdrola, whose investors own the biggest stake in CMP’s parent company, Avangrid.

She has put in many hours in permit proceedings and lawsuits related to the project. And even with construction underway, she’s hopeful that any one of the challenges still out there — including a statewide referendum set for November — will spell its demise.

But as CMP cuts more trees, as it plants more poles in the ground, the company’s risk of failure could be growing smaller.

“The risk is becoming increasingly small, looking at the whole perspective,” said David Littell, a former state regulator and lawyer who now advises governments and private clients on utility issues.

He said that in addition to the physical work being done, CMP and Hydro-Quebec are also providing millions of dollars in benefits — such as investments in electric vehicle infrastructure or broadband service — on an expedited schedule.

Littell said a case is building that could make the project a legal fait accompli.

“You know, sometimes facts make a difference. CMP is clearly working hard to change the facts on the ground by building corridor and making payments,” he said.

Littell said it’s far from a slam dunk though. And one legal expert, Portland lawyer Jamie Kilbreth, is counting on the state’s courts.

“There are a lot of issues here that all interrelate. And they all suggest that CMP’s rush to build this thing may be a mistake,” he said.

Kilbreth said there is precedent from the Maine Supreme Judicial Court that could overcome any “vested rights” that CMP may develop on the ground.

And he is a lead lawyer in a suit brought by a bipartisan group of lawmakers, conservationists and others contending that the state leased lands for the project to CMP without seeking a two-thirds vote of the Legislature that’s required by the Maine Constitution.

“Regardless of what happens with the referendum, if they can’t get two-thirds legislative approval to cross the public lands then they are going to have to find a new route and start the permit process all over anyway,” he said.

If Kilbreth’s clients win the case, that is.

CMP has already made an appeal in that case to the Maine supreme court that could slow it down, and some observers think that’s a stalling tactic by CMP so it can pile more poles into the ground before any court takes decisive action.

Thorn Dickinson, CMP’s top executive on the project, steadfastly avoids the question of whether its aggressive construction schedule is keyed to any legal risks.

“We’re going to continue to be nimble; we’re going to focus on the work that we can get done, and we’ll deal with the challenges as they come up. We’re not ready to move our commercial operation date at this point,” he said.

Earlier deadlines have been missed, though, and CMP has pushed its planned in-service date to May of 2023.

And in a proceeding at the Federal Energy Regulatory Commission, CMP is seeking a quick decision in a contentious dispute with NextEra over transmission system upgrades at the Seabrook nuclear power plant.

System regulators say the upgrade is needed for grid safety before CMP energizes the new powerline. CMP says NextEra, which owns the nuclear plant, is dragging its feet on planning and scheduling that upgrade, forcing delays that could stall the powerline’s in-service date past 2023.

In a sworn affidavit, Dickinson of CMP alleges that NextEra offered a quid-pro-quo: agree to buy electricity from Seabrook at an above-market rate, and NextEra would expedite the upgrade process.

Starting two weeks from now, tree-cutting on CMP’s corridor project will be barred through the end of July. That’s required to protect summer habitat for the northern long-eared bat, a threatened species.

This article appears through a media partnership with Maine Public.