At top of map: 'United States, Department of Interior, Geological Survey. Professional Paper 374-E, plate 1.' In lower right corner of map: 'Geology mapped by C.R. Longwell.' Relief shown by contours. Includes seven colored cross-sections. Scale 1:125,000 (W 114°50´--W 114°20´/N 36°10´--N 35°10´). Series: Shorter contributions to general geology. Professional paper (Geological Survey (U.S.)) 374-E. Originally published as plate 1 in: Reconnaissance geology between Lake Mead and Davis Dam, Arizona-Nevada / by Chester R. Longwell, published by the U.S. Government Printing Office in 1963 in the series Shorter contributions to general geology and as Geological Survey professional paper 374-E.
Colorado River-Hoover Dam. Views of Boulder Dam printed in book or magazine; numbers on the photo correspond to particular areas described at the bottom of the image. Site Name: Hoover Dam (dam)
First 40 foot slab of concrete poured in lining diversion tunnels for the construction of the Boulder Dam, now called Hoover Dam. Site Name: Hoover Dam (dam)
Construction site of the Boulder Dam, now known as Hoover Dam. Marion electric drag line with 5 cubic yard capacity bucket loading gravel. Site Name: Hoover Dam (dam)
Boulder Dam (now called Hoover Dam) construction. Trucks hauling 2-cubic-yard buckets, bringing concrete from the mixing plant for invert lining. Site Name: Hoover Dam (dam)