The U.S. Army reopened Fort Fletcher on October 11, 1866 at the confluence of Big Creek and its north fork, mile north of the previous site. This time, the purpose of the fort was to protect workers building the Union Pacific Eastern Division railway westward, parallel to the Smoky Hill Trail. A month later, in November, the Army renamed the post Fort Hays after Brig. Gen. Alexander Hays who was killed at the Battle of the Wilderness during the American Civil War. On June 7, 1867, a severe flood nearly destroyed the fort, killing nine soldiers and civilians.