Could these be the remains of rotary ON?  I snapped the pictures during a trip to Alaska in the summer of 96.  The plow was found  around milepost 5 out of Skagway, Alaska.  I have compared some of the cowling features to pictorials and they look as if  they could match.  The stories I have read would also tend to support this as being the site where ON was dumped to help keep the roadbed from washing out.

A close relative of rotary ON, Rio Grande rotary snow plow OM sits in the yard in chama on September 15, 1996.  I love the cloudy afternoons in Chama it makes for a great backdrop for picture taking.  One day I will get around to building a model of this rotary.

The Chama yard is a great place to measure and photograph equipment for future model building purposes.  On August 13, 1994 I spent the afternoon measuring and photographing Ex-D&RGW flanger OK.  I have started on a 1:24 scale model of the flanger although there won't be much snow in Phoenix to try her out.