(AP Photo) This is a downstream view of the Hoover Dam taken Aug. 12, 1933, showing the immense …

(AP Photo) This is a downstream view of the Hoover Dam taken Aug. 12, 1933, showing the immense ...

(AP Photo)
This is a downstream view of the Hoover Dam taken Aug. 12, 1933, showing the immense concrete blocks rising from the bedrock of Black Canyon’s floor, which will be the core of the dam. Concrete was poured into the forms at the rate of about 6,000 cubic yards daily.