The U.S. Army Corps of Engineers (CE) has monitored microearthquake activity near selected projects to enhance seismic safety. Ten monitoring programs were completed. Six programs are in progress. Thirteen of the programs were initiated to document induced seismicity. The three remaining programs were intended to examine microearthquake activity in areas of known or suspected active faulting. The programs have been operated by contractors, such as the U.S. Geological Survey and various universities. The CE Districts, Seattle and Huntington, are operating programs directly. The programs documenting induced seismicity have shown that CE projects have little or no local seismic activity. The programs have measured ambient microearthquake activity at reservoir sites before filling and have recorded activity for several years after filling. Programs have been completed at one injection well and seven reservoir projects. Only four of the ten completed programs ran their full intended course. In some cases, the projects were deauthorized or transferred out of CE control. Five programs are in progress at reservoir sites (or proposed sites).