Sky High: A YA Dystopian Novel in Bloomington, MN

In a post apocalypse world, a group of teenage orphans are determined to escape the tortures of a mile-high city government-a literal platform-city in the sky. They seek the refuge of a utopian society they believe is rumored to exist.
However, all is not well when they reach terra firma. They escape a communist dictatorship only to land in a world of rogue tribes and hybrid monsters.