The unique haystack is made by these devices known as a beaverslide. Originally known as the Beaverhead County Hayslide, the name was shortened later. They were invented in the early 1900’s by ranchers in the Big Hole area. As the haystack is not portable once constructed the beaverslide is moved to make another stack. Also this lack of portability makes it only useful for feeding your own livestock, not selling hay to others. A few ranches around Montana still use horses to operate them, more practical as fuel prices rise.
The model behind glass is in the Beaverhead County Musuem.