Tracy Sole Bruce D. Smith 2000 <p>During July, 1997, twenty four Schlumberger dc resistivity soundings were made in the Boulder watershed and adjacent areas (fig. 1). The objective of geophysical studies in the watershed is to map subsurface lithologic, structural and hydrologic features important in controlling possible ground water contamination from mining activities and for design of remediation efforts. These studies are part of an abandoned mine land study (http://amli.usgs.gov/amli/ ) of the Boulder Basin mining district ( http://www.deq.state.mt.us/mtmines2/linkdocs/techdocs/73tech.html ). </p> application/pdf 10.3133/ofr00110 en U.S. Geological Survey Schlumberger DC resistivity soundings in the Boulder Watershed, Jefferson and Lewis and Clark counties, Montana reports