Officials with the US Army Corps of Engineers shift from controversial proposals for the Missouri River to controversial proposals for the Mississippi River tonight. The Corps is holding its final public hearing on the draft plan for a $2.4-Billion proposal to build seven new locks and lengthen five others on the Mississppi and the Illinois Rivers upstream of the Gateway Arch in St. Louis. Barge operators say it is needed to releave congestion on the Mississippi. Environmentalist object to adding any more infrastructure to the lock and dam system that already exists. Congress will make the final decision.