Thanks for the reply, Tom. I found what I was lookin for in Serving with Honor: The Diary of Captain Ethan Allen Pinnell of the Eighth Missouri Infantry:

Sept 7, 1863:
…Our works extend from the river two miles below the city, to the eastern part of Crystal Hill, a distance of six miles. Gen’l Fagan’s Brig. is on the extreme right, Parsons on Fagan’s left, Frost in the center and McRae on the left.