The Southwest light-rail line now has a contractor to build it and up to $435 million to start construction this winter.

The Metropolitan Council, which will build and operate the line, awarded a $799 million bid on Thursday to Lunda/C.S. McCrossan, the lone bidder left in a process that dragged on for more than a year.

“This is an exciting, big project and we’re excited to be a part of it,” said Brent Wilber, Lunda Construction Co.’s vice president for Minnesota.

When the council unanimously approved the contract late Thursday afternoon, those in the Robert Street chambers burst into applause.

“This is an incredible moment; after two decades of work we’re finally ready to begin construction,” said Alene Tchourumoff, the outgoing chair of the Met Council.

The past day or so has been a whirlwind for the often-controversial $2 billion project — the region’s third light-rail line — that will link downtown Minneapolis to Eden Prairie.

The furious activity commenced once the council received word Wednesday that the Federal Transit Administration (FTA) cleared the way to begin construction of the nearly 15-mile line. The FTA issued a “letter of no prejudice,” which makes early construction work on the project eligible for federal reimbursement.

The FTA is expected to pay $929 million to help build the project, with the remaining portion covered by state and local funds.

Met Council Member Gail Dorfman, a former Hennepin County commissioner, noted that she brought her 11-year-old son to one of the first meetings she attended for the project. “Now he’s 30,” she said.

Other members expressed relief that the project has cleared an important milestone, admitting that at times it was challenging.

Earlier in the day, the Hennepin County Board and its rail authority entered into a grant agreement with the Met Council for up to $435 million to begin construction and pay for light-rail trains. The money comes from a local sales tax for transit and, to a lesser extent, property taxes in the county.

The board also approved an additional commitment requested by the FTA for up to $200 million, about 10 percent of the project’s overall cost, to cover any funding shortfalls or cost increases.

Holding up the letter from the FTA, County Board Chairwoman Jan Callison said, “This very simple letter belies how momentous this is.”

Outgoing board member and longtime transit advocate Peter McLaughlin said Southwest is part of a transit network akin to the federal interstate highway system built in the mid-20th century. He acknowledged there were skeptics about public transit in the region over the years.

“A lot of people called the [Blue Line light rail] a train to nowhere,” he said. “Well a lot of people are going to nowhere every day.”

The lone dissenter on the board was longtime light-rail opponent Jeff Johnson.

“The cost is enormous to build and subsidize forever,” he said. “It will do nothing to relieve traffic congestion.”

The line is slated to travel through 16 stations in St. Louis Park, Hopkins and Minnetonka, as well as Minneapolis and Eden Prairie. Passenger service is expected to begin in 2023.

Construction of the line, the state’s largest public works project, is complicated. It includes work on 36 bridges, eight tunnels, 15 at-grade light-rail road crossings and more than 100 retaining walls. More than 7,500 construction jobs are expected to be created to build the line, with a $350 million construction payroll.

Early construction activities include “staffing and equipment mobilization,” demolition and utility work. Heavy construction will begin in earnest in 2019 and last through 2022, with testing of the system and light-rail trains from 2022 to 2023.

Not everyone was jubilant about the news. Mary Pattock, a spokeswoman for the Lakes and Parks Alliance, which is suing to stop the project, said, “I’m surprised the FTA awarded any money at all before finding out whether construction could be halted either by our lawsuit or by tunneling only 18 inches away from the Calhoun Isles Condominium — an 11-story concrete building.”

The condo complex is located along the Kenilworth corridor between Lake of the Isles and Cedar Lake in Minneapolis, and some residents have expressed concern about the light-rail line.

The FTA noted that “the authority to incur costs provided in this letter does not constitute an FTA commitment that future federal dollars will be approved for this project.”

But the council noted that the FTA has never reneged on a grant once issuing such a letter.