Derick Prelle was appointed CEO of Mills Fleet Farm in June by KKR & Co., the private equity firm that purchased the retailer last year. Prelle is leading efforts to double the company’s footprint over the next six years and expand into new markets; he’s already helped open a long-awaited location in Monticello. (Mills had added only six stores in the last 10 years.) To position the company for growth, Mills is building a 1.1 million-square-foot distribution center in Chippewa Falls, Wis., slated to open in 2018.