Old River Control Structure of 1973 almost caused the control structure to fail. Integrity of the Old River Control Structure, the nearby Morganza Spillway, and other levees in the area is essential to prevent such a diversion. Jeff Masters of "Weather Underground" noted that failure of that complex "would be a serious blow to the U.S. economy." The present Old River Control Structure was completed in 1964 and expanded in 1990. The first two floodgates are the Low Sill Control Structure, which regulates routine flow in the waterway, and the Overbank Control Structure, in use only when the Mississippi exceeds its banks. A navigation
120th Ohio Infantry May 1. Ordered to join Banks at Alexandria on Red River Expedition May 1. Embarked on steamer "City Belle". Action en route at Snaggy Point May 3. Over 200 men captured. Those who escaped were formed into a battalion of three companies and marched to Alexandria. Retreat from Alexandria to Morganza May 13–20. Mansura or Marksville Prairie May 16. Duty at Morganza until September. Expedition to mouth of White River and St. Charles September 13–20. Expedition to Duvall's Bluff, Ark., October 21–27. The regiment lost a total of 300 men during service; 2 officers and 17 enlisted men killed or