This unused Mike Roberts card C628 gives both of the dam’s names but, as usual, we are never certain which state should get credit for it.  Then called the “highest in the world, 727 feet” in the caption, Wikipedia tells us the honour now goes elsewhere:  “Currently, the tallest dam in the world is Nurek Dam on the Vakhsh River in Tajikistan. It is 984 feet (300 meters) tall. Hoover Dam is 726.4 feet (221.3 meters) tall”.  Awww …  Grade: 1