Hi Dan,
It took me a while, but I went back over the maps and satellite photos on the Terraserver site. I have identified only three possible routes the RR could have taken to Dixie Summit if one heads east from Prairie City.
In the attached satellite photo, Route 26 is visible along the northwest side of the view, with Dixie Summit at the top. A forest service road is visible cutting off from south side of Rt. 26 right at Dixie Summit and winding its way down into the canyon of Jeff Davis Creek. This road contains a tight lariat loop which stands out clearly in the photo. It is possible that some parts of this road could be on the old grade although the road's location does not completely hold up for RR use as you get further down the canyon. Just south of the Summit, Rt. 26 runs just to the west of the forest road and has a much easier alignment with gentler curves and grades. It would be hard to imagine a location engineer overlooking this route unless some sort of ROW dispute prevented its use by the RR. If the Rt. 26 route were taken at this point, it looks like the RR would not have needed switchbacks to attain the summit, although switchbacks would probably have been necessary to get the RR down into Jeff Davis Creek from Rt. 26.
There seem to be 3 possible routes the RR could have taken north from PC. A route along Rt 26 and Dan's Creek is the western most of these possible routes. A route up Jeff Davis Creek is the middle alternative. A parallel canyon to the right of the lower part of Jeff Davis canyon is the eastern most alternative. A possible fourth route combines parts of the Rt. 26 and the Jeff Davis routes.
There are no indisputable map or photo clues that woul indicate ROW turning north into either of these routes from the valley to the south, although the road arrangement at the south end of Jeff Davis Creek canyon does look promising.
The maps are clearly inconclusive. Short of actually exploring the ground in question - there is no way to tell which one was THE route. So the uncertainty as to the RR's actual route from PC to Dixie Summit is likely to remain until someone has a chance to check it out.
Anyhow, I appreciate your help and because of your earlier questions about Terraserver, I thought you'd be interested in this. If you've already found this stuff out please ignore.
You can't get a hit from the Terraserver search engine if you search on "Dixie Summit, OR", even though the location is clearly marked on the topo map. You either have to search on "Prairie City, OR" or "Austin, OR" and drill down to magnification level 4 before you come up with something you can work with. The inital large scale map of PC is very old and unusable until you get down into the lower magnifications - the smaller scale maps are newer. The surrounding large scale topo maps are a little better but nearly as unusuable. Once you get down to the smaller scale maps, you will have to navigate to adjacent maps from the PC or Austin maps using the arrows around the edges of each map or image.
Thanks again,
Glenn
