This coin is interesting because it contains a unique banner which is unlike most banner stickers you will find. This sticker has wedged ends on the red portion of the banner vs. the very common straight edged banner. Also the waving pattern on this sticker is more desirable because the banner ripple is convex vs. the very typical concave pattern with most banner stickers.
The Powder House Lodge was established in 1948 and is still in operation today. This sticker was most likely from the 1950s. The lodge is actually located just north of Keystone in the Black Hills of South Dakota. It is most likely that these coins were either sold in the gift shop or were given as change in the Powder House restaurant located at the lodge.