A crane flies over a street sign near a rule measuring the height of the floodwaters in feet, in St. Francisville, Louisiana May 17, 2011. Scores of US heartland rivers from the Dakotas to Ohio have flooded following a snowy winter and heavy spring rains, feeding near-record crests on the lower Mississippi River. [Photo/Agencies]

A deer wades through water in the Atchafalaya River after water from the open Morganza Floodway invades their habitat near Krotz Springs, Louisiana May 17, 2011. Scores of US heartland rivers from the Dakotas to Ohio have flooded following a snowy winter and heavy spring rains, feeding near-record crests on the lower Mississippi River. [Photo/Agencies]