Re: 80 years ago on the Sumpter Valley...

I think you're right about the snow train going over the hog law. Somewhere in Ron Harrs collection I found a timecard for a crew that stated they had been bucking snow from...I think it was Bates to somewhere above Whitney. The crew actually went over the 16 hours and it said they went back to Whitney to spend the night! This was in 1922 if I remember right.
It would be interesting to find out more about the snowplow, i.e. when was it built, how many men did it require to operate, where was it stationed most of the time,etc. I know that the Roadmaster was usually in the pilot house to control the flangers so that they wouldn't rip out any of his switches...