New Construction Lake Saint Louis | AMS Expansion Mandan | Administration Building Expansion A 33,000 square-foot addition in 2016 provided a new lobby, kitchen and lunchroom, boardroom, conference rooms and work space facilities. With the expansion, the Mandan campus is 130,000 square feet. Today, over 420 employees work on the campus. In 2016, a 44,000 square-foot expansion provided additional work spaces and doubled facility space for Automated Mailroom Services. With the expansion, the Lake Saint Louis campus covers 179,000 square feet.