WASHINGTON -- Decades of debate over the proposed St. Croix River crossing ended Thursday with a five-minute vote in the U.S. House, which approved the plan overwhelmingly and sent it to President Obama for his signature.

The 339-80 vote easily surpassed the two-thirds needed to fast-track the project, a move made necessary after Minnesota Gov. Mark Dayton gave Congress a March 15 deadline before reallocating state funding.

"This is it!" said Rep. Michele Bachmann, who carried the bill in the House. "After decades of bureaucratic holdups and frivolous lawsuits from radical environmentalists, the people of the St. Croix River Valley will finally have their bridge."

A unanimous Senate approved the same measure last month, belying the discord that underlies the $690 million project. Congressional action was needed to exempt the bridge from the Wild and Scenic Rivers Act, a landmark law from the 1960s sponsored by former U.S. Sen. and Vice President Walter Mondale.

Mondale lobbied against the bridge, calling it "a brutal assault on one of the most magnificent rivers in America."

Barring any unforeseen legal impediments, work on the new bridge could begin in the fall of 2013 or the spring of 2014, according to Minnesota Department of Transportation spokesman Kevin Gutknecht. With a three-year construction schedule, traffic could be traversing the new cable-stayed span by 2016.

The bridge has pitted environmentalists against labor-allied Democrats, who joined Bachmann in promoting a project that lies in her district.

For Bachmann, final passage of the bill represented a singular legislative achievement after three terms in Congress and a run for president.

The opposition was led by Rep. Betty McCollum, D-Minn., whose district is expanding under redistricting to include the bridge site in Oak Park Heights.

"Every policy debate has two sides," McCollum said. "I worked hard to reflect the voices of Minnesotans in the 4th District, as well as those Stillwater and Oak Park Heights residents who are deeply concerned about this mega-bridge project."

The debate pitted McCollum against fellow Democrat Amy Klobuchar, who championed the bill in the Senate with the backing of Dayton and Wisconsin's Republican Gov. Scott Walker, who formed a bipartisan cross-river coalition.

Dayton, who forced the issue by threatening to yank the money for other transportation needs, said he was "delighted" by the House vote.

Amid the swirl of competing interests, the endgame was dominated by three powerful Minnesota women: Bachmann, who shepherded the bill through the House; McCollum, pressing for a scaled-down design, and Klobuchar, who drafted the final legislation and got it through the Senate.

"At some point, after 30 years, it's time to build the bridge, and do it the right way," Klobuchar said.

Oak Park Heights in limbo

Obama is expected to sign the bill, despite misgivings expressed by some administration officials about exempting the bridge from current environmental law. But should the deal get inked, another hurdle remains.

Oak Park Heights, where the bridge would be built, has not issued the required "municipal consent" for the project. Millions of dollars in utility relocation costs along Hwy. 36 have not been funded, and the Oak Park Heights City Council recently passed a resolution opposing property tax increases to pay for the work.

Mayor David Beaudet said Bachmann called him Thursday with a promise. "She stands ready to help the city with its utility issues," said Beaudet, who nevertheless remains skeptical.

Stillwater Mayor Ken Haryski said the immediate objective is to "get the president's ink on that bill." After that, he said, state legislators will have to work hard to find funding for Oak Park Heights. "In the end it wasn't a Democratic bridge or a Republican bridge," he said. "It was a bridge for the people."

Several Stillwater business owners who want a new bridge to relieve downtown traffic congestion were toasting cautiously with champagne Thursday. "It's one hurdle that we're over," said Meg Brownson, who owns a shop near the south end of Main Street. "I wouldn't be surprised if something else comes up. We're not going to get overly excited. It's going to be a celebration but we're not going to be jumping up and down."

'Magic moment'

Opponent Roger Tomten said his Stillwater neighbors will be surprised by the size of the new bridge, which will stand nearly three times taller than the Interstate 94 bridge 6 miles downriver. Freeway speeds on the new bridge will cause noise and land-use problems around the river, said Tomten, a spokesman for an alternative design known as Sensible Stillwater Bridge Partnership.

"I'm not sure where the fiscal conservatives are these days. I think they must be on spring break," Tomten said. "People wonder why we're having federal budget problems. This seems to be a case study of that."

Opponents focused on the fiscal and environmental costs of the bridge to rural Wisconsin, deeming it a "Bridge to Nowhere." But backers dismiss concerns about the "wild and scenic" character of the crossing site, noting its close proximity to factories, a power plant and two state prisons.

McCollum and her allies, including Rep. Keith Ellison, D-Minn., also portrayed the bridge as an "earmark." Bachmann and Klobuchar dismissed that characterization, noting the long and open process that led to the vote.

With passage assured in the last minute of the vote, changing tallies indicated opportunistic vote switching. Opponents attributed it to pressure from AFL-CIO activists at the Capitol. But Bachmann blamed it on what she called McCollum's "false" earmark rumors.

Despite the lopsided vote, "this was no sure thing," Bachmann said. "We never took this for granted. ... It was a magic moment."

Kevin Diaz is a correspondent in the Star Tribune Washington Bureau.