American Rivers, a Washington-based nonprofit conservation group, says it has placed the Mississippi River back on its endangered list after having been off the list for three years.
In particular, the group says the Upper Mississippi River faces threats from reconstruction projects of the lock and dam system by the U.S. Army Corps of Engineers. Additionally, the group says the big river's tributaries are high in nutrients and sediment flowing into the Mississippi.
They also say wildlife habitat is in bad shape.
American Rivers says the Mississippi River is ranked 10th on its list for 2004.