Tri Cities that I know about and is known very well out west and especially in the northwest and intermountain west is in Washington and makes up Pasco, Richland, and Kenniwick.
Not sure how much you would ask for such a name but the term/prefix "tricities" would be just as popular to that region as would Fresnopest or Renopest would be for those locations. It wouldn't be anything negative for the name, only positive.
Not sure if that helps or not but what I thought about after seeing your post.