"The 'Beaverslide was invented and patented by two Big Hole Valley ranchers, Herb Armitage and Dade Stephens in 1910, under the name 'Sunny Slope Slide Stacker.' Because of the swampy ground commercial equipment has never worked very well in the Big Hole, and so locals have been creative in adapting devices to suit their needs. Use of the Beaverslide spread throughout much of the western US and Canada, but the Big Hole is now one of the few places where it is still commonly used."

From Hay in Art: the definitive website on the subject, I've no doubt, an encyclopedic treatment of a worthy topic. I've always loved driving around Wisdom, Montana, the last refuge of traditional haystacks.

Thanks to Prairie Mary.