Re: Multi-use ?

El Coke,
The lumber companies did indeed use the SV main line a good bit. In fact, I believe the Baker shop was a joint SVRy/OLC operation; logical since OLC was the parent company. This would have required a main line run every time the geared power came out of the woods for service or repair. There's a picture somewhere, probably in Rails, Sagebrush & Pine, of an OLC shay on the "speedway" in Bowen Valley.
Ditto what you said about the Heislers - IIRC, Weyerhauser in WA state purchased one of the 120?-Ton Three-truck Heislers specifically for a 10 or 15 mile haul over NP or MILW main line. This train was said to regularly operate at speeds in excess of 25 mph.
On a mostly unrelated note, please let me compliment you on the fine painting of the SV three-spot, cover of the new printing of "Log Trains of Southern Idaho" which I've only just seen. I made one very small contribution to that book, took the Author's photo on the dust jacket. The author was a most modest & unassuming man, he told me that when the publisher asked for a recent picture my snapshot of him in the cab of SV #100 was the only one he had that was less than 15 years old!
J