“In order to develop atomic weapons during World War II, the federal government needed a source of energy to power the top-secret Oak Ridge National Laboratory. Out of that need the Fontana Dam, Fontana Lake and Fontana Village were born. Located in Graham and Swain counties in western North Carolina, the region is collectively known simply as Fontana….
“Completed in 1944 at a cost of over $70 million, the dam is 480 feet tall and almost ½ mile wide at its crest. The Appalachian Trail winds across the top of the dam as it makes its way from Georgia to Maine. Hikers have named the nearby trail shelter the ‘Fontana Hilton,’ since it is one of the few stopovers with hot showers nearby.
“Fontana was not designed as an overflow dam, so it has a somewhat distinct appearance: its length is accentuated by the absence of water spilling over the top. Whenever the reservoir reaches capacity, water is released downstream through spillways tunneled through the base of the dam.”
— From Fontana Dam at DigitalHeritage.org
I’ve seen such celluloid tape measures dating back as far as 1900, not long after the introduction of celluloid political buttons, but this one probably appeared on a souvenir shop shelf circa 1950.