BG Cooper's report to BG Steele lists Lt. Ballenger as KIA at Honey Springs. This is the first report of him being a doctor that I've seen; thanks for the info.
Both Federal and Confederate dead were buried at or near the place of death. In some places the ground was too hard -- or too shallow (8" - 14" of soil atop a thick shelf of rock) -- for burial at the exact location. There are accounts of mass graves, but extensive searches over the past thirty-five years have yielded no results.
BG Cabell's chief of staff writes of arriving at the battlefield and seeing a mound of dirt thrown up over a line of bodies "their straight, black hair identifying their race."