Saving The Mississippi River From Itself -- And From Us

SIMMESPORT, La. -- Inside a nondescript building in a remote lowland bordering the Mississippi River, biologist Paul Hartfield points to a map on an overhead screen as he explains to a group of fellow biologists how he tracks a prehistoric fish that inhabits local waters. Hartfield's talk is mostly inside-baseball stuff, though the ramifications extend far beyond the building, in part due to a dramatic scene unfolding just outside the windows.