The chief executive officer at Cheyenne Regional Medical Center has announced she will resign Sept. 2. Margo Karsten will become the new CEO for Banner Health in Northern Colorado. She will oversee three Banner hospitals: North Colorado Medical Center in Greeley, McKee Medical Center in Loveland and Banner Fort Collins Medical Center in Fort Collins. Banner Health in Northern Colorado has about 5,000 employees and a total payroll of $250 million.