Confederates executed locally in 1865 most likely ended up in Maplewood Cemetery, which was the burial grounds for Confederates based there prior to Union occupation. That area now has a section fenced off from the larger modern cemetery that has a large old wrought iron sign at that part’s entrance saying “Confederate Cemetery.”
Interestingly, in another section of the cemetery I found a soldier from Company K, 42nd Missouri Infantry who died in February 1865, Pvt. John G. Dean.