During the global environmental and geological changes, landmasses underwent massive changes.  Floods, caused by drastic climate changes and the melting of icecaps in the Arctic and Antarctic regions, submersed much of the Mississippi Basin in North America.  Earthquakes along San Andreas caused much of California and the West Coast to break off into an island chain, which later sank as a result of the floods.  Only the higher elevations of the East Coast survived, cut off from the mainland by intrusions of the Atlantic Ocean.

                UNICorp abandoned the smaller islands created by the shallow sea, and these became pockets of non-UNICorp habitations.  On the larger island, UNICorp built corporate farms for growing vegetables and fruits.  These products are shipped across the narrow channel, defended from Overworld rebels and raiders by patrol boats.  On the mainland, UNICorp has maintained control of most of the mountainous regions, leaving the lowlands and desert areas to the Overworlders.

                Along the coasts and scattered along rivers, Overworlders have built towns and villages.  However, in the Death Valley area, southeast across the low hills and flatlands, the region is irradiated from nuclear testing and UNICorp dump sites.  A handful of Metagenic humans and creatures are able to survive in that region.

                The shallow waters if the former Mississippi Basin became the home of a rather large colony of seaweeds.  The wide sea has become a Sargasso, choked with kelp and other ocean life that has adapted to the polluted waters.  There are rumors of great cities filled with wealth under the waters, but the creatures that have moved into the Sargasso have been able to keep any adventurous souls from leaving the submarine "el Dorados."