From the back of the box:
"No One Gets Outta Here Alive!
That's what they say about Devils Tower. Of course there are a few exceptions to every rule, and with a little savvy, a few well-placed bullets, and more than it's share of luck, your posse just might be one of them. Getting to the monolith across the Weird West is the easy part. Deadling with the mysterious crossbreeds and the other denizens of Devils Tower-that's something else entirely.
The Devil's Tower: Fortress o' Fear boxed set comes crammed with everything you need to know about Devils Tower and the creatures inside it. It includes a 96-page adventure book, a 32-page digest-sized book about the crossbreeds' alien technology, and two full-color, double-sided poster-sized maps detailing the region around Devils Tower, as well as a dozen levels of the interior of the hollowed-out monolith. As a special bonus, there's also a 32-page digest featuring a preview of Deadlands: Hell on Earth, finally revealing some of the long-held secrets of the Reckoners!
It's the most unusual challenge any posse has ever faced-and the most deadly. With the fate of the Weird West at stake, though, no true hero could refuse the call to arms."