Well, my mileages go from Memphis up the river as opposed to downriver from Cairo but here's what I have:

Fort Pillow - 46 miles upriver from Memphis
Fort Wright - 40 miles up (the newspaper is incorrect - Fort Wright and Fort Randolph were the same fort, located at Randolph, Tenn.)
Fort Harris - 6 miles up from Memphis
Fort Pickering - at Memphis

From what I understand Fort Harris, and a comparable fort on the Arkansas side of the river, Fort Rector, were both abandoned by the Confederates well prior to Memphis being threatened.