The Great Mississippi and Missouri Rivers Flood of 1993 (or "Great Flood of 1993") occurred in the American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 Midwest, along the Mississippi

Mississippi River

The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

 and Missouri

Missouri River

The Missouri River flows through the central United States, and is a tributary of the Mississippi River. It is the longest river in North America and drains the third largest area, though only the thirteenth largest by discharge. The Missouri's watershed encompasses most of the American Great...

 rivers and their tributaries, from April to October 1993. The flood was among the most costly and devastating to ever occur in the United States, with $15 billion in damages. The hydrographic basin affected cover around 745 miles (1200 km) in length and 435 miles (700 km) in width, totaling about 320,000 square miles (840,000 km²).