The Mississippi River Sandbars and Islands IBA encompasses the Mississippi River and its associated islands of sand / gravel bars (some with bottomland forest). The now heavily channelized Mississippi River meanders less than it did historically, but periodic flooding and inundation of these island habitats occur. None of the IBA is publicly-owned conservation land.

Several nesting records of Interior Least Tern are from the Mississippi River Sandbars and Islands IBA, where some nesting colonies have contained over 300 nests. In 2005, just over 1,000 individuals were counted during annual surveys by the US Army Corps of Engineers. Colony sizes fluctuate annually. Bald Eagles also nest along wooded islands and riparian forest edges adjacent to the IBA.

These bottomland / island habitats used by nesting Least Terns are subject to inundation during flood events that may be made more severe due to river containment for flood control and barge traffic. High numbers of terns have been recorded in recent years, although it is unclear whether this is the result of local production or emigration from coastal populations.