Bill, both Charles & Drew gave you good information. While I can't even hazard a guess as to what you saw from the train that may have been an old logging ROW, I can say that Medford Corporation liked Willamettes. Out of a roster of 7 steam locomotives, 3 were from that manufacturer. While the number 2 was scrapped, the 4 is being worked on by the Southern Oregon Chapter of the NRHS at Railroad Park in Medford and the 7 is the one that you saw in Dunsmuir. The 4 spent her entire working life in & around Medford, the 7 was acquired rather late and worked in the woods, frequently at Medco Pond. Medco Pond can be reached by paved road. It is beyond Butte Falls & can still be seen today.
Drew may have given you a link to his nice image of the 7 while still on Medco property.