I'm reading Boneshaker by Cherie Priest right now. It's pretty good so far, I guess, although at times the writing seems amateur-ish. It's an alternative history book set in Civil War-era Seattle, with a steampunk twist. During the Gold Rush, a scientist built an enormous drilling machine called the Boneshaker. But a test run went awry and destroyed half of downtown Seattle, as well as releasing a deadly gas into the city called the Blight. The book is set a few years later, after an enormous wall is built up around the ruined Seattle, and tells the story of a woman and her son. If you're into steampunk it's a good read.