A federal judge on Thursday blocked a proposed $668 million St. Croix River bridge on grounds it violates the Wild and Scenic River Act.

Judge Michael Davis ruled that the National Park Service (NPS), in approving the proposal, ignored its contrary position in 1996 that a "massive" bridge south of Stillwater would have a "dramatic and disruptive" affect on the river's scenery.

It's uncertain what will happen next until the 93-page ruling is reviewed, said Chris Stein, superintendent of the St. Croix National Scenic Riverway, which the NPS manages. Stein said he did not know whether the Park Service would appeal the ruling.

The bitter war to build a bridge on one of the region's most scenic and best-known waterways began more than 40 years ago. Even then, there was a desire to replace the 1931 Stillwater lift bridge that was built for occasional small vehicles traveling between Minnesota and Wisconsin.

In recent years, at least 16,000 vehicles a day cross the lift bridge, leading to traffic backups in downtown Stillwater and delays when the lift section is raised to let boats pass underneath.

The most recent court hearing was Sept. 14, when the Sierra Club said a four-lane bridge would ruin the scenic riverway and hurry contamination of the Lower St. Croix, a federally protected river that the Minnesota Pollution Control Agency lists as impaired.

"It's important for everybody to understand that we don't celebrate lawsuits," Sierra Club spokesman Jim Rickard said Thursday. "We'd much rather take a collaborative track. If there's a victory to be declared, it's a victory for the river."

But Gary Kriesel, a Washington County commissioner who favors a new bridge in part to relieve traffic congestion leading to Stillwater's aging lift bridge, said he was disappointed in the ruling and angry with the Sierra Club.

"I don't think people are going to stand for this much longer," said Kriesel, who's forming a "bridge advocacy" group of Minnesota and Wisconsin residents. Traffic congestion in Stillwater is taking a toll on the environment because of long lines of idling cars, he said.

A mile south of the lift bridge

The proposed bridge would have gone from Oak Park Heights, just south of Stillwater, to two highways in Wisconsin about a mile south of the lift bridge.

Failure by the Park Service to acknowledge its previous opposition, "let alone explain why, in its opinion, a change is justified, is the hallmark of an arbitrary and capricious decision," wrote Davis, chief judge of U.S. District Court in Minneapolis.

Davis concluded that the NPS and the secretary of the Interior violated the U.S. Wild and Scenic Rivers Act by approving the bridge.

The NPS can't authorize the current bridge proposal or otherwise assist in construction unless it issues a new "Section 7 evaluation" that addresses the court's concerns, Davis wrote.

Davis was critical of how the NPS justified the current proposal, writing that "common sense" shows that the 2005 version was similar to the rejected 1996 version in purpose, location and physical characteristics.

"The National Park Service fails to explain how combining a group of apparently ineffective measures, all of which relate to shoreline actions, can create an effective mitigation package, when, in 1996, it concluded that no available mitigation measures could significantly reduce the negative visual impact of a similar bridge," Davis wrote.

The evaluation the NPS completed in 2005 resulted from years of meetings with 28 stakeholders, Stein said.

Hopes were high among political leaders on both sides of the river that the proposed bridge would move forward. If money became available, construction was scheduled to begin in 2013 at a cost of $668 million, six times what was estimated just a decade ago.

The Minnesota Department of Transportation's request for a $300 million federal stimulus grant failed last month when the project was passed over. Engineers have said the price tag increases by $2 million each month the project is delayed past 2013.

"We won't know how much of a setback this is until we've had time to understand the court ruling," said Todd Clarkowski, MnDOT's engineer in charge of the bridge project. MnDOT wasn't named in the suit.

"Trust me, it's eventually going to get built," said Kriesel, who hopes the federal government will have a change of heart. "If there are stimulus dollars out there, let's put people to work. This isn't just fluff."

Bridge construction could employ 2,800 people, he said.

Rickard, who belongs to the Sierra Club's St. Croix Valley Interstate Group, said he hopes the ruling will lead to a renewed debate of alternatives to a large bridge.

"The Sierra Club is not against a replacement bridge," he said. "We're against a massive design like the one that's been proposed."

Kevin Giles • 612-673-4432