In two field seasons (2008-2009), the ISGS and McHenry County collected 31 continuous lithologic cores to bedrock (17 wireline-mud rotary, 14 rotosonic), which included downhole geophysical logs at each location (gamma ray and electrical resistivity). The ISGS also collected approximately 90 km of 2D geophysical profiles (seismic (51 km) and electrical resistivity (39 km)). The geophysical datasets help geologists further decipher the character of glacial sediments below land surface. These field data have been the key datasets for regional and local geologic interpretation in the County.