Great find! Yes, a hotel key fob is exactly what it is. The only problem is figuring out where the hotel was. Just 'cause it is from the Helena hotel, doesn't mean it was located in Helena - you may have to do some research from the ca. 1900 directories - but there definitely was one there. The nasty shape was to discourage customers from putting it in their pocket and forgetting to return the key to the desk when they checked out. These are very collectable (doesn't necessarily equate to valuable), and Montana collectors will be very interested. IMO, it would look great framed with a print of a photo of the hotel - here's one of the one in Helena for instance.
John in the 208