Geology of the Straight Creek tunnel site, Clear Creek and Summit Counties, Colorado, and its predicted effect on tunnel construction

The purpose of this report is to present the preliminary results of the geologic and geophysical research conducted by the U. S. Geological Survey at the surface over the proposed Straight Creek tunnel. The results are interpreted and predictions are made, based primarily on statistical analyses, as to the probable geologic conditions at the depth of the tunnel, and how these conditions may influence the engineering design and construction of the tunnel. It is expected that continued geologic and geophysical research by the Geological Survey, and we hope by others also, during progress of the tunnel will result in an evaluation of the methods here employed that will be of general interest to the geologic and engineering professions.