Interesting directory, Don.

Here's image of a 1963 map (more recent than your directory) of the Henderson area. For those interested, it locates the area called "Pittman" in the upper left corner, on Boulder Hwy, where the Magnesium Casino was located. Also note the road in upper right corner which intersects Boulder Hwy in Henderson -- called "Vegas Wash Hwy" in those days. Now known as Lake Mead Blvd. (Was this the area of recent flooding?)

The Magnesium Casino name would have been derived from the large Basic Magnesium plant, largest employer in Henderson in the 1940's, producing key ingredient (magnesium) for bombs for the war effort in WWII. Lots of streets in Henderson had (or still have) metal names, like Manganese, Magnesium, Lead, Copper, Zinc, Nickel, Gold, Platinum, etc.

This is probably elementary info for older LV collectors, but may be of interest to newer collectors...weaving historical information into those round things we collect.