Three books are very helpful; 1) Rails, Sagebrush & Pine, by Mal Ferrell 2) Sumpter Valley Railway 3) Sumpter Valley Logging Railroads, both by Alfred Mullett and Leonard Merritt. These books have historic information, lots of photos, and some maps, though none are compared to the modern road system. I got interested in SVR a few years ago and am searching for the same information and maps as you. I can't find any. I hate computers, but getting on this site has been the smartest thing I could do. I'm sure you've seen the posts from Bret Bane, Jim Grigsby and Taylor Rush regarding all things SVR. All three volunteer on the "new" SVRR and have been great help. Bret Bane provided me a number of discs full of SVR info, including a number of maps, with a full set of platt maps for the SVR from Baker to Austin, but none that compare to the road system. I wanted the same kind of map as you, the whole SVR, Baker to Praire City, sidings and stations, including the logging lines, all overlaid on a modern map that includes modern roads, as accurately as possible. To that end, I have been using Google Earths mapping tools to plot the entire route of the SVR from Baker to Austin. Knowing the area from exploration, using the platt maps and the satelite views along with some GPS data, I think (???) it is fairly accurate. I have maps for the section from Austin to Prairie City but need more time exploring that end of the RR to be semi-accurate. Not very computer savvy, so I'm not sure how to get this information uploaded to you. I'll play with it a little bit. If you can find a good map, let me know. It would save a lot of time and effort!!!
Brian