RESPEC performed the geotechnical engineering characterization for the Deep Underground Science and Engineering Laboratory (DUSEL) in the former Homestake Mine located in Lead, South Dakota.  The DUSEL is planned to be a National Science Foundation- (NSF-) sponsored Major Research Equipment Facility Construction (MREFC).  The geotechnical engineering effort included the initial mapping, drilling, in situ testing, and laboratory testing required to provide a better understanding of the rock properties and to characterize the rock in the areas proposed for future development.