The transverse prestressing of wood r¡ ras conceived of in 1976 as a method for reha-bílitating nailed laminated wood decks. Using high-strength prestressing steel, a pernanent pressure is introduced normal to the dírection of the laminations to provide high interlaninate shear strength and inproved load¿ listribution. The success of this new concept in rehabilitation resulted in its beconing the subject of a rnajor re-sêarch and developnent program conducted by the Ontario Ministry of Transportation and Communications (MTC). The extensive work perforned by MTC over the past 7 years has led to the for¡ nulation of a set of conpre-hensive design specifications for prestressed wood. The objèctive of this paper is to outline the design, construction, and load testing of the worldrs first new pre-stressed woocl bridge. The bridge was desígned by MTC and constructed by the Ontario Ministry of Natural Resources (lqNR) over the Ì {est River, on a logging access road, near Espanola, Ontario, in 1981. The design process with reference to the new desígn specifications, which. have since been adopted by the Ontario Highway Bridge Design Code, ís discussed. The field constructíon is outlined highlighting the prefabrication and assembly of the prestressed wood super-structure. The load testing of the bridge in 1982 and the subsequent evaluatíon of the test results are described. The MNR deternined that the West River bridge cost only two-thirds of the steel structure originally proposed for that sÍte. The load testing and subseguent evaluation indÍcated that this prestressed y¡ ood brídge is an extremely rigid structure with considerable reserve s trength.