SIOUX FALLS, S.D. — The family of a man who opened Sioux Falls’ first Burger King more than 40 years ago is selling that restaurant and 25 others in South Dakota and Minnesota.

Tom Walsh Sr. and his family are expected to sell the 26 restaurants next week to Chicago-based Cave Enterprises, the Argus Leader reported. Sioux Falls is home to 11 of the restaurants.

Walsh said he told managers the news Monday, calling it “the hardest business thing I’ve ever done.” He said the timing and buyer felt right.

“Their culture, values, priorities, were the best and most in line with what our values and culture was,” he said.

The Dakota King businesses employ about 1,200 people. Dakota King president Tom Walsh Jr. said the existing team will stay in place.

“We’ve had four record years in row and we’ve been franchisee of the year for operators of 20 stores or more for four years in a row,” Walsh Sr. said.

Cave Enterprises plans to continue the Dakota King charitable programs, including one that helps financially support employees during emergencies.

At one time, Walsh’s Dakota King organization operated 60 restaurants from Wisconsin to Nebraska. In 2015, he sold his five Burger King locations in North Dakota. Earlier this year, he sold five locations in Duluth, Minnesota, to Cave Enterprises.

Walsh opened the city’s first Burger King in 1975.