Superb footage! Interesting to see WM #6 as the pusher on the Bald Knob train. As I recall, it mainly served as the Whittaker engine from the mid-90's through the late 2000's, since the curve on the mainline at the "wye" was too tight for it to navigate. I'm assuming on this particular day, the Bald Knob train must have been turned on the wye and run the last few miles to the top in reverse. (Either that, or #6 was dropped and #2 proceeded solo from that point.)
A late reply to your comment: your first assumption was correct. MSR&LHA actually rebuilt the wye in early 1997 and extended the tail track to accommodate an entire train for this exact purpose. Then, a few years later, CSRR reconfigured the mainline curve nullifying this effort. I wish someone had taken a photo of the train sitting at Bald Knob in reverse. I don't think I've ever seen one. I'm not sure why they didn't just leave Big Six on the Whittaker train until the curve was rebuilt, seems like an odd decision to make, but then there's always been plenty of head scratchers in Cass history when it comes to logic.