I fear this post might be well behind the times but in case its not, I recently found out that that the University of Tennessee Press has put pdfs copies of the Betts' Chickamauga maps online. These maps were created when the battlefields of Chickamauga and Chattanooga were preserved. Henry Boynton was the first park historian and wrote the official battle history, placed the iron markers you see on the field today and also had troop movement maps created to accompany the text. You can buy these maps in an altered state today at the park, basically one map now has info that originally appeared on 3-4 maps. But now UT Press has put the original 13 maps online here.
They did this in conjunction with the publication of "The Battles of Chickamauga and Chattanooga and the Organizations Engaged" by Henry Boynton, edited by Timothy B. Smith. Smith has basically combined three Boytnon books into one volume and provided some other notes on Boynton. I have not held a copy of Smith's version yet, I knew he was working on it but did not realize it was out already. I actually do have Boynton's other books but I would like a modern reprint so I don't have to worry about ruining my 100 year old versions.