Below is an 1869 map that incorrectly show's Cochran's on Middle Boggy in the Choctaw Nation instead of on Clear Boggy (Boggy Creek) in the Chickasaw Nation. No general land survey had been done of the Indian Territory so the maps were based on the accumulation of information from expeditions, boundary and road surveys, journals, and memory. Errors were perpetuated until general land surveys were performed in the late 1800s. This 1869 map is based predominately on pre-Civil War maps so this is very similar to what officers had available to them.
It is my assumption that the so-called Battle of Middle Boggy (or Muddy Boggy) was actually fought at or near Cochran's on Clear Boggy (aka Boggy Creek). I believe Col. Phillips - referring to his map - saw Cochran's shown on Middle Boggy in the Choctaw Nation, and reported such as the location of the battle. I have not found a shred of evidence to support the Atoka vicinity for this battle -- but I continue to search.
This map also shows Delaware Ridge that Patti Rochette posted some info about a couple of days ago.