White Mountain Sun

In an alternate 2015, dinosaurs were recreated thanks to a certain combination of avian and reptilian DNA. Young dinosaurs have successfully been hatched, and for the past five years, they've been introduced to the public and most currently reside in the National Zoo (along with a few select other zoos). Scientists are, as of now, studying them, and the world's interest in dinosaurs has gone up farther and faster than it's ever been. The National Zoo is constantly even more packed than in our world, and the dinosaurs are cared for, famous, and leading the best possible lives.
Except for that's not what's happening at all.
First of all, they aren't dinosaurs--they're genetic monstrosities, walking chimeras who never should have been hatched.
Second, they're not even scientifically accurate--bald and lipless and with patterns that look like scars. The Velociraptors have been warped the most of all, to the point where they don't even behave like the extinct animals they parody. Modern paleontologists are disgusted.
And, third of all, they're not happy--they know of a world outside the walls, a world where they can roam free and wild, like true animals are meant to. They know that they can escape, but the question is how.
So, when the pack of Velociraptors in White Mountain Zoological Park manages to escape, what's stopping them?
What's stopping them from reaching the wild and feeling the sun on their backs?
What's stopping them from being free?

Warnings apply for swears and some violence, but nothing too terrible. The zoo is fictional, but the setting is basically just the American South. Tags and cover may be updated. Not entirely sure about genre.