WASHINGTON — The U.S. House of Representatives approved a new bridge over the St. Croix River on Thursday, voting 339-80 to send a bill authorizing the project to President Obama for his signature.

The bill provides an exemption to the Wild and Scenic Rivers Act, which protects the St. Croix River and has prevented the bridge project from going forward for several decades. The $700 million four-lane bridge has bipartisan support from lawmakers in both parties — Democratic Sen. Amy Klobuchar was the lead architect of the legislation and steered it through the Senate in January, and Republican Rep. Michele Bachmann sponsored the bill in the House.

Klobuchar credited that bipartisan support and the coordination between Minnesota and Wisconsin officials with getting the bill through Congress.

“We really worked together: Republicans, Democrats, Wisconsin, Minnesota in a way that had never happened before,” she said. “This is [about] two states that have been struggling to get something done for years, towns that have had congestion with cars built up, an old bridge that is literally breaking parts into the river, and it was time to get it done and the federal government shouldn’t stand in the way of that.”

“This is the most important vote to affect the 6^th District of Minnesota in over 50 years,” Bachmann said. “I am absolutely thrilled because now we will finally get this commonsense bridge.”

Both Klobuchar and Bachmann said they’d talked to Transportation Secretary Ray LaHood, who told them he expects Obama to sign the bill into law. Obama has not formally taken a position on the bill as of Thursday morning, according to the White House.

Gov. Mark Dayton, who had set a March 15 deadline for congressional action on the bridge, said in a statement that he was “delighted to see this important project move forward; this new bridge is urgently needed.”

Eighty lawmakers, 64 of them Democrats, voted against the bill, spurred on by opposition from Rep. Betty McCollum. The St. Paul Democrat led the charge against the bill during floor debate on Wednesday night and said she was disappointed with the result this morning.

“Every policy debate has two sides and 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,” she said in a statement. “Congress’ passage of this $700 million bridge bill doesn’t diminish its excessive cost, size, negative effect on Highway 36 traffic congestion or its adverse impact on the St. Croix River.”

But pro-bridge Democrats worked to solidify support for the bill in the hours before the vote. Two Wisconsin Democrats, Reps. Tammy Baldwin and Ron Kind, sent a letter to lawmakers Wednesday plugging the support of labor unions like the AFL-CIO, which estimates the bridge’s construction will create 6,000 jobs.

In the end, only one Minnesotan, Democrat Keith Ellison, joined McCollum in voting against the bill.

Devin Henry can be reached at dhenry@minnpost.com. Follow him on Twitter: @dhenry