Come summer, employees of Minnesota’s largest suburban county will have a new boss for the first time in more than 20 years.

Dakota County Manager Brandt Richardson announced Wednesday that he’ll retire in May after nearly four decades in public service. He’s been in the manager position since 1992.

“I think a person in my capacity needs to consider the needs of the organization, not just my personal needs,” he said. “And as I think about it, I think there’s no better time for me to leave than right now.”

Richardson, 66, is the county’s chief executive, overseeing nearly 2,000 employees. He’s responsible for long-term planning, putting together an annual budget and implementing County Board decisions.

The search process for a new administrator, an appointed position, will begin almost immediately. County Board Chairwoman Nancy Schouweiler, who recently announced her own plans to retire at the end of the year, said commissioners will likely start discussion at next week’s board meeting. The search is “probably our top priority for the year,” she said.

Like other local governments, Dakota County has experienced significant staffing changes in recent years — the staff turnover rate more than doubled between 2010 and 2014 — but Richardson said the bulk of management turnover has already happened.

“That’s part of my thinking here,” he said. “We have a great leadership team in place.”

Richardson started his government career in Dane County in Wisconsin, then worked for the Minnesota Department of Natural Resources and the now-defunct Minnesota Water Planning Board. During his tenure as county administrator, fast-growing Dakota County has become home to the state’s first bus rapid transit line, expanded its parks and trails network and constructed most of the government buildings that stand today.

Richardson plans to step down from his full-time position by May 1, but has offered to stay on part-time to help with the transition. After that, his plans are up in the air — he’d like to continue public service in some form, and he’s hoping to spend some time trout fishing.

“To have this part of my life unplanned, it’s a little unnerving,” he said. “That’s one of the reasons it’s been so hard for me, actually. This has been my life for so many years.”