A typical plaque found on properties listed in the National Register of Historic Places
The National Register of Historic Places (NRHP) is the
United States federal government's official
districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance. A property listed in the National Register, or located within a National Register Historic District, may qualify for tax incentives derived from the total value of expenses incurred in preserving the property.
Since about 1900, the Black Canyon and nearby
Boulder Canyon had been investigated for their potential to support a dam that would control floods, provide irrigation water and produce
hydroelectric power. In 1928, Congress authorized the project. The winning bid to build the dam was submitted by a consortium called
Six Companies, Inc., which began construction of the dam in early 1931. Such a large concrete structure had never been built before, and some of the techniques were unproven. The torrid summer weather and lack of facilities near the site also presented difficulties. Nevertheless, Six Companies turned the dam over to the federal government on March 1, 1936, more than two years ahead of schedule. (Full article...)