Thanks for your reply: the Beshoar lead especially (book now on order).
The possible (I use that word now) location of the graves is from an early 1930's survey of the Elm Creek Station site conducted by the Adams County (Nebraska) Historical Society. At the time, the markers were still visible, but illegible. The survey was very specific as to the location of the graves. That information is courtesy of the current ACHS director. It was provided after my wife and I had visited both the Elm Creek Station site and the attack site -- they're about two miles apart. Both are on private property.
I plan to revisit the ACHS archives later this spring; I'm recently retired and finally have the time to devote to this project. Other than a search for the markers, no other activity is contemplated. Your concern regarding grave disturbance is understandable and your cautionary note appreciated. Thanks.
As to the identity of the perpetrators, I admit to a bias. Col. R.R. Livingston, who was detailed to investigate the incident, was from Plattsmouth, NE, where I reside. Livingston initially believed that the Pawnee were guilty; however, in his report he concludes that they were not. This was after the Pawnee male population was paraded past the survivors. He was satisfied that all males were accounted for. Possibly he consulted the then recently completed Pawnee Reservation census. Anyway, 150 years later the discussion continues as to who they were or were not. I’m very much interested in Beshoar’s take.
Enjoy your spring,