Geology of the eastern part of the Harold D. Roberts Tunnel, Colorado (Stations 690+00 to 1238+58)

Summary of the engineering geology of the Harold D. Roberts Tunnel, Colorado

“…From station 343+00 to the East Portal (sta. 1238+58) original geological investigations were of a reconnaissance nature and were entirely inadequate (Warner and Robinson, 1981). Because of the interest created by the driving of the tunnel, additional mapping of the surface geology above the tunnel was undertaken under the sponsorship of the U.S. Geological Survey and the University of Colorado, and data of the kind that would have been obtained during an adequate original program of geological investigations are now available (Robinson, Warner, and Wahlstrom, 1974).…”