Coincidentally, I discovered last night that I have a portion of the interview of one William Culbertson taken from the Indian-Pioneer Papers. Unfortunately, I only copied the first page of the interview. However, this page begins with his recollection of moving to Sulphur Springs (or Sulfur Springs) and describes the nearby merging of the roads from Ft Gibson and Ft Smith to Boggy Depot where they fork again. If you'll send me your email address (just click on my name above), I'll send you what you what little I have.
Have you run across reference to "Winchester" or "Winchester's" or maybe even "McKinney's Winchester" Station. It is shown approximately in this general Atoka to Stringtown area on some old post war maps. I wonder if the name had anything to do with Gov. Winchester Colbert, though there were others named Winchester, of course. It may just be an error of which there are many on pre-allotment maps.