Question - The SVRy route west from Dixie Summit

Hi,
I've spent a relaxing afternoon playing on the Terraserver site. Using the photos and topo maps I've been able to follow line north from Prairie City and south from Larch and Whitney. The stretch between Tipton and Austin is especially easy to follow since the USGS has thoughtfully marked the old grade as such.
But when I get to the map marked "11 Km NE if Prairie City, OR (dated 11 July 1988)", I am having trouble figuring out where the switch backs were located. I can see where Route 26 crests Dixie Summit and assume the RR more or less followed this alignment from the east. (Actually from the satellite photos it looks like the old grade is running along the base of the foothills immediately to the south of the highway - akthough that bit *could* just be wishful thinking since I would rather the grade be intact.) I believe I have also followed what I take to be the grade coming up the West bank of Dad's Creek - where it appears to come to a little clearing and deadends. (I *think* I followed the correct route anyhow. The map in RS&P is no help. But the best alignment seemed to run from Prairie City due north along the road and then northeast across open country to Dad's Creek.)
Its easy to see why switchbacks were needed between Dad's Creek and Dixie Summit. But where were they located? Were they further up alongside Dad's Creek? Or was that elsewhere?
Thanks in advance for any help you can provide.
Best Regards,
Glenn