SANDPOINT — A federal judge’s ruling is marked by victories and defeats on both sides of a lawsuit aimed at thwarting development of the proposed Rock Creek mine in northwestern Montana.

U.S. District Judge Donald Molloy released a comprehensive 124-page opinion Tuesday detailing his rationale for a March 29 decision to remand the project’s record of decision and final environmental impact statement back to the U.S. Forest Service for further analysis.

“The blueprint for the Rock Creek Mine has always been flawed, and the impacts excessive,” Jim Costello of the Rock Creek Alliance said in a statement which accompanied the release of Molloy’s opinion.

The Rock Creek Alliance coalesced with a dozen other conservation groups to mount legal challenges over the project’s approval.

The groups view the court’s ruling as a win that provides an opportunity to provide permanent protection to the Cabinet Mountains Wilderness, water quality and habitat for grizzly bear and bull trout.

Molloy found that the Forest Service’s record of decision was arbitrary and capricious because the agency admittedly used insufficient information concerning bull trout.

“The statements by the Forest Service and the Fish and Wildlife Service in 2003 show the agencies knew at the time that information on bull trout habitat and population was inadequate,” Molloy said in the opinion.

The court further ruled that the agency failed to minimize adverse impacts to the environment.

“The court correctly found that the Rock Creek mine violates environmental and public land laws that are meant to protect water quality, fisheries, and the public from industrial mine pollution,” Roger Flynn of the Western Mining Action Project said in a statement.

However, the court also made a number of rulings favorable to the Forest Service and Revett Minerals, the project’s developer and an intervening party in the litigation.

Molloy rejected a plaintiffs’ motion for a preliminary injunction and turned down some of their claims that the Forest Service violated the National Environmental Policy Act.

The conservation groups argued that an ore evaluation adit and the ensuing mine should have been evaluated as independent projects, but Molloy disagreed.

“The decision not to consider Phase I as a separate alternative does not constitute a failure to take a ‘hard look’ at the alternatives. The Forest Service reasonably argues that it was required to analyze Phases I and II together because of their contingent nature,” Molloy said.

Although the court found that inadequate bull trout information was used in the record of decision, it also ruled that the Forest Service took “substantial steps to ensure adverse impacts to bull trout were mitigated.”

Despite some of the setbacks, Revett Minerals President John Shanahan said he was “encouraged” by aspects of the court’s opinion.

“We believe that it provides guidance and a road map,” Shanahan said on Thursday. “We really do believe that the Rock Creek project can be developed in an environmentally responsible manner and we have every intention of doing that.”