David Mortenson will succeed his father as leader of M.A. Mortenson

M.A. "Mort" Mortenson, who 46 years ago took over his father's construction firm and grew it into one of the nation's largest commercial builders, will retire and turn over leadership to his son, David, the firm said Monday.

"It's time to transition to the next generation," Mortenson, 78, said in an interview.

The Golden Valley-based company built or renovated many of the best-known commercial structures in the Twin Cities, including Target Field and the recently updated Orchestra Hall. It is now building the Vikings stadium.

The firm is also known for its work on the Walt Disney Concert Hall in Los Angeles, the Denver Art Museum and dozens of military and government facilities. The company, one of the nation's top builders of large-scale alternative energy installations, posted revenue last year of $3 billion and employs about 3,800.

Mortenson said it was "thrilling" to hand his son leadership of the company that his father started in 1954.

"I've always loved construction and this company," he said. "My dad was a tradesman and a hard worker. That was just embedded in my approach. In the early days, we did it all."

David Mortenson, 49, who has been president, joined M.A. Mortenson in 1991 after college and three years as a Navy officer. As chairman, he will lead the board of directors and oversee the policy and direction of the firm.

"I'm honored to help lead the company my grandfather founded and my father has led and grown for 46 years," David Mortenson said. "Our success as a company is a result of the hard work of so many people."

Tom Gunkel, who joined Mortenson out of college in 1983, will continue as chief executive.

Mortenson survived the Great Recession that wounded many other developers and contractors. Although business dropped by 20 percent at Mortenson, it did not lay off workers. The firm generally doesn't build unless it has a buyer or tenants lined up.

Mortenson executives learned a valuable lesson during the late 1990s technology boom, when it built a huge data center in Southern California on speculation. A prospective buyer backed out as the boom went bust in 2000 and Mortenson was stuck with an empty building.

"That was a $10 million lesson," M.A. Mortenson said. "Somebody eventually ended up buying it at a bargain price."

Mortenson, in addition to constructing sports stadiums, hospitals and office buildings, is the biggest builder in the country of wind farms. In the desert east of Los Angeles, the firm is working on what will be the nation's largest solar-energy installation.

Among its other work in the Twin Cities, the firm is one of three firms contending to build a mixed-use complex on the north end of Nicollet Mall in downtown Minneapolis. It has proposed a 31-story tower on the site.

Neal St. Anthony • 612-673-7144