Building Products, also known as B.P.I. of South Dakota, distributes wholesale building materials to retail lumberyards throughout the Midwest. The company was founded in 1957, servicing customers from a warehouse in Watertown, S.D. In 1975, the company expanded with the purchase of Lumberman s Supply Company in Sioux Falls, S.D. This location was eventually consolidated with the original Watertown warehouse in 1991 and assumed all of the sales territory previously serviced by that distribution center. That same year, Building Products founded its Forest Products division, which distributes rough boards, pattern boards, hardwood boards, cedar dimensions, cedar boards, sanded plywood, particle board shelving, wood grade stakes and bridging to more than 700 lumber yards. Building Products is based in Watertown, S.D.