It's like a tricycle, but it has skids instead of rear wheels. In his 1869 book Velocipedes, Bicycles, & Tricycles, the pseudonymous author Velox describes this tragically unpopular invention:
The American ice velocipede (Fig. 34) is a much more sensible contrivance. It is literally skating by means of machinery. The design originally appeared in Harper’s Weekly, and the machine is intended to be used on ice or frozen snow. The driving-wheel is armed with sharp points to prevent the possibility of slipping, which proved to fatal to M. Dreuze’s machine. The hind wheel is replaced by a pair of gigantic skates or runners, similar to those used in sleighs or ice-boats. It is hardly likely to have a fair trial in England.
Link -via Ask the Past
I was in Grafton, Utah, last month at the ghost town where they filmed that scene, although I didn't recognize it. Or maybe I recognized it subliminally because I re-watched 'Buth Cassidy' and when I did, I said, "Hey! That's Grafton!"