President Lyndon Johnson even flew out from Washington, D.C., to survey the destruction and pledge all necessary assistance to flood-ravaged communities.

The Mississippi River is approaching levels that could trigger a full operation for the first time in four years. "We do this when the river is high enough," Corps spokesman Matt Roe said.

Three state wildlife management areas and one national wildlife refuge have hunting closures in place due to flooding. Two more areas may close.

A conservation organization has named the Mississippi River as the most endangered river in the country. Every year, the advocacy group American Rivers publishes a list of the 10 U.S. rivers it ...

President Lyndon Johnson (circled) surveys the swollen Mississippi River in Lilydale during a visit to St. Paul on April 14, 1965, two days before the floodwaters crested at a record 26.4 feet.