by Cherie Priest.
This book had a bit of everything: steampunk, alternate history, and zombies! During the Gold Rush to the Yukon, the Russians held a contest - building a machine to drill through the ice. Leviticus Blue built such a machine - The Bone-Shaking Drill Engine - which turned 1860s Seattle into a wasteland. A gas (the Blight) was released that would turn anyone who breathed too much of it into a "rotter." Years later, Zeke (Blue's son) wants to learn more about his father and finds a way into the walled off portion of the city. Briar Wilkes, his mother, has no choice but to follow him - and meet lots of great characters along the way.
This book had a lot of mystery, not a lot of which was solved - but then, this is supposed to be the beginning of a trilogy, so perhaps answers will come. I did really enjoy this book: it was fun, and consistent without taking itself too seriously.