I think this is the photo Bret is refering to.
It is quite likely that, once the stuck trains were dug out, the rescue train had to plow its way back to Austin. The need to refuel the geared locomotives would have increased the time required considerably. I have no other details but, reading between the lines, there would be considerable work after the trains were dug out. If the line below the stuck trains was not plowed they would probibly have to plow out the yard at Larch, and drag both trains up to there in order to get the plow on the lower end. After three days the stuck locomotives could have run out of fuel and had to empty their tanks and boilers. No mention was made of the line from Sumpter to Baker, but if no plow was available at Baker they might have plowed that as well. The snow might have been less at this lower elevation and could be handled with a flanger, with which #17 was equipped.
I'm not sure what the man on top of the plow is doing, but his position would seem precarious if they derail or hit an obsticle.