Methods to identify and subsequently seal surface water loss zones in stream channels were tested by the U.S. Bureau of Mines at Staub Run, a first-order stream near Frostburg, MD, that partially overlies abandoned coal mine workings. Conventional stream gauging was conducted to establish discharge patterns before and after stream sealing. Electromagnetic terrain conductivity surveys were performed within the stream channel to identify zones of increased relative water saturation to depths less than 15 m. Zones of increased conductivity were generally found to be associated with areas exhibiting statistically significant (p < / = 0.05) gauged flow losses. Conversely, zones that exhibited declining conductivity delineated areas where between-station flows were not significantly different. Using this information on potential loss zones, an experimental grouting procedure was applid by injecting an expandable polyurethane grout to a depth less than 1 m into the alluvial streambed over a 180-m section of the stream channel. Before grouting, the study section exhibited a 24-l/s flow loss; first-phase grouting reduced this to a 14-l/s flow loss; with a second-phase grouting the losses were only 3 l/s.