There is a black marble monument at Marks Mill which reconizes by name all the Known men, both Union and Confederate, which died as a results of that Battle. But does not seperate them by sides or Units. It simple reconizes all the men as a single group no matter which side they fought on.
Also there is a modern markers with the 5th Kansas Cavalry marker at Pine Bluff the reconizes the 1st Indiana Cavalry. These being the two Union Units involved in the battle of Pine Bluff.