The operators of the the Viking Lumber Mill on Prince of Wales Island had argued that the massive timber sales would be necessary for its operation. (File photo by Ed Schoenfeld/CoastAlaska)

A federal judge has dealt a potentially fatal blow to what would’ve been the largest timber sales in Tongass National Forest in decades.

The court challenge ends the U.S. Forest Service’s plan to open up 24,000 acres of old growth forest on Prince of Wales Island to commercial logging. It also halts road building for the 15-year project.

Conservationists had successfully blocked the federal government’s attempt at pre-clearing large amounts of timber for sale without identifying the specific areas where the logging would actually occur.

But after the Forest Service argued throwing out the entire project would harm what’s left of Southeast Alaska’s timber industry, Judge Sharon L. Gleason gave both sides a final chance to make a case for and against allowing the agency to correct deficiencies in its review and move forward.

Her final ruling came down squarely against the Forest Service’s plan. In a 14-page order signed on Wednesday, Judge Gleason ruled the “the economic harm” of invalidating the timber sales “does not outweigh the seriousness of the errors” in the agency’s handling of the project.

“It’s exactly what we asked for and we couldn’t be more pleased,” said Meredith Trainor, executive director of the Southeast Alaska Conservation Council which brought the lawsuit.

The ruling, she says, effectively sends the feds back to square one, triggering a fresh environmental review under the landmark National Environmental Policy Act, “which includes requesting public input on the specific areas that they want to log, which is what was a big sticking point in the basis of this case.”

Alaska’s timber industry reacted with disappointment to the ruling.

“The Southeast timber industry is primarily reliant on timber sales from the (Tongass National Forest),” Tessa Axelson, executive director of the Alaska Forest Association wrote in a statement. “This decision further threatens the viability of Southeast Alaska’s timber industry.”

The Prince of Wales Landscape Level Analysis was the first time the agency used this approach for environmental review on an Alaska timber sale. The ruling affects these projects including the Central Tongass Project near Petersburg and Wrangell as well.

But the judge’s decision does not affect other aspects of the Prince of Wales project. That includes habitat and stream restoration and investment in recreational trails and cabins that had been supported by a resident advisory group. It’s unclear what progress will be made in those areas as most non-timber sale related projects remain unfunded by the Forest Service.

The federal agency can appeal the decision. It did not return calls for comment.

This article has been updated to incorporate the Alaska Forest Association’s statement.