Keywords: Bulkhead gate structure at inlet portal of Diversion Tunnel No. 4. Semi-circular structure in front of portal is... - NARA - 293759.jpg Scope and content Photograph from Volume Two of a series of photo albums documenting the construction of Hoover Dam Boulder City Nevada General notes 293759 Local identifier Department of the Interior Bureau of Reclamation Engineering and Research Center 05/18/1981 - 03/04/1988 NARA's Rocky Mountain Region Denver NRGA Building 48 Denver Federal Center West 6th Avenue and Kipling Street Denver CO 80225-0307 1932-10-26 Record group Record Group 115 Records of the Bureau of Reclamation 1889 - 2008 Record group ARC 444 Photograph albums compiled 1903 - 1972 Series ARC 293611 File unit File unit ARC Variant control numbers NAIL Control Number NRG-115-CONSTPHO85006-BC21432 Other versions <gallery> File Bulkhead gate structure at inlet portal of Diversion Tunnel No 4 Semi-circular structure in front of portal is - NARA - 293759 tif tif </gallery> NARA-cooperation PD-USGov Construction of the Hoover Dam |