Comprehensive Railroad Atlas of North America [Book]
A friend turned me towards the Comprehensive Railroad Atlas of North America (published by SPV) as a resource to help me with finding old railroad lines and reconstructing them on Google Maps (see RR-XING Google Map project). He loaned me the Dakota's and Minnesota atlas and I was impressed. I actually ended up ordering both the Dakota's and Minnesota as well as the Prairies West atlases from the SPV Web site: www.spv.co.uk
The nice thing about these atlases is not only does it show you where abandoned and current lines crossed the states and what towns they connected, but it also gives information on sidings, ownership, trackage rights, and the like. It truly is comprehensive.
For me, a person very interested in Burlington Northern and Chicago and North Western, it is nice to have it show the former owners of the lines as well as the current ones. In Nebraska, I am able to see what track was the Fremont Elkhorn and Missouri Valley Railroad vs. Chicago, Minneapolis, St. Paul and Omaha, both later became subsidiaries of CNW, but it was nice to have them separated out. In Minnesota I am able to see the differences between the Northern Pacific and Great Northern routes before they merged with the Burlington.