Wireless Smart Sensor Networks (WSSN) facilitates a new paradigm to structural health monitoring (SHM) for civil infrastructure. Conventionally, SHM systems employing wired sensors and central data acquisition have been used to characterize the state of a structure; however, wide-spread implementation has been limited due to difficulties in cabling and data management, high equipment cost, and long setup time. WSSNs offer a unique opportunity to overcome such difficulties. Recent advances in sensor technology have realized low-cost, smart sensors with on-board computation and wireless communication capabilities, making deployment of a dense array of sensors on large civil structures both feasible and economical. Wireless smart sensors have shown their tremendous potential for SHM in recent full-scale bridge monitoring examples. However, structural damage identification in WSSNs, a primary objective of SHM, has yet to reach its full potential. This paper presents a full-scale validation of the decentralized damage identification application on the Imote2 sensor platform on a historic steel truss bridge. The SHM application for WSSN developed in the previous research is further combined with continuous and autonomous monitoring application. In total, 144 sensor channels and one base station have been deployed on the bridge for damage localization. The efficacy of the developed application has been demonstrated to compare the damage identification results with the traditional centralized processing.