OK...so, correct me if I am wrong, but your major concerns are (1) what would draw characters from the "outside world" to this location and (2) if you have a campaign based in this location, there is not much to do.
Depending on the composition of your character group, what would you think of the following:
(1) Coalition expansion group (from any time period of Rifts Earth) looking for natural resources and/or looking for new DNA (should they be from Lone Star) and/or eliminating the threat of this new form of magic that has been rumored to exist in that area.
(2) A group of magic users interested in learning the secrets of a new form of magic.
(3) A group of scientists and/or scholars looking to expand their knowledge of pre-historic times and creatures as the knowledge from Pre-Rifts time is extremely limited in that area, not to mention the historical knowledge of NASA and Disney
(4) And the simple point that many in the Rifts world just like to explore.
(5) Not to mention being Rifted their just to add flavor to a long standing campaign by taking the techies and mages out of their comfort zone for a while.
As far as living their goes, the simplest would be an invasion by one of the other powers of Rifts earth motivated by one of the aforemetioned plots.
That is just what I could rattle off of the top of my head.
