Hennepin County Commissioner Mark Stenglein, a longtime County Board member who cast a critical vote in 2006 to build the Twins' ballpark, said Friday he'll leave office this spring to become president and CEO of the influential Minneapolis Downtown Council.

He will replace longtime head Sam Grabarski, who has seen several projects come to fruition during his 16 years running the council.

Grabarski signaled last year his plans to step down but will remain as president emeritus to wrap up a few projects, including the International Downtown Association's convention in Minneapolis this fall.

Stenglein, 56, of northeast Minneapolis, will move to his new job on June 1. His County Board seat will be filled at the general election in November.

"We like Mark primarily for his leadership abilities," said Downtown Council Board Chairman Elliot Jaffee, president of US Bank Twin Cities Market. "He cares about the community, he knows how to get things done and he's been a terrific supporter of downtown Minneapolis."

Stenglein said he believes that life "should be broken up into thirds: a third to learn, a third to earn and a third to serve. ... I decided that this was something I could take my toolbox to."

His departure could leave the Hennepin board without a key vote for a new Vikings stadium should that issue come before commissioners at some point. Like Grabarski, Stenglein strongly supports a downtown stadium and said that task will be "right at the top" of his priorities for the next two years.

His main job will be implementing the goals of the council's 2025 Plan, a 15-year blueprint that lays out a number of downtown projects. The council performs the function of a chamber of commerce for downtown and includes most of the region's largest businesses.

State Sen. Linda Higgins said Friday that she intends to run for Stenglein's seat. The Minneapolis DFLer announced in November that she will not seek reelection to the Legislature this fall.

Stenglein has been a reliably moderate-to-conservative voice in his 15 years on the County Board, but his politics often have been tough to pigeonhole.

He's run mostly as an independent, but sought DFL Party backing in his last race in 2010. An enthusiastic backer of big construction jobs, he launched the African American Men Project to improve county policies toward black males.

His résumé includes several years in the private sector, working in Kuwait and Nigeria as an accountant and then starting and running a successful small business leasing single executive office suites.

In 1996, Stenglein, who had never held office, narrowly defeated DFL incumbent Sandra Hilary for the County Board. He ran on a platform of welfare reform, property tax relief and crime for the Second District seat, which represents a long horizontal stretch through the center of the county from Plymouth to St. Anthony.

Board Chairman Mike Opat, who has often lined up with Stenglein on key votes, said the board will miss his experience and good humor.

"It's a great opportunity for Mark and it's a great opportunity for downtown, because he's always been passionate about trying to improve downtown," Opat said. "Target Field is one example, but so is his support for transit and the library merger."

Kevin Duchschere • 612-673-4455