The way I understand it, this is an example of a gear driven engine (missing the under-gear in this photo), used to move timber out of the forest to the main road, where another style of power would be used to move it to the mill. These were wood burner steamers, and rather flexible so that the wheels could stay on the tracks in the rough forest. The bulbous smoke stack is designed to minimize embers from escaping and setting the forest on fire. Small embers circulate within, then fall down to the outer shell. The Hiesler series was originally designed for logging, but was used more in the lake states. The cylinders are side to side instead of being length ways with the frameworks. The bigger version had tender wheels behind that were also powered like the Shays.

This locomotive is outside the Air Museum in Tillamook Oregon. It is, of course, Photoshopped and Tone-mapped to the max. Hope you enjoy it.