I'm the author of the ASHFALL three-and-a-half-ology: ASHFALL, ASHEN WINTER, SUNRISE, and DARLA'S STORY.
David Estes's Fire Country is a worthy addition to the post-apocalyptic literature. His world building is rich, detailed, and believable. The plot features Siena, a young woman born into a hyper-patriarchal tribe known as the Heaters. She's portrayed with a deft touch--she's not perfect--but I nonetheless found myself empathizing with her and cheering as she struggled to surmount her fate. The voice is a particular strength of this novel. Estes makes extensive use of invented language and unconventional grammar. I was thankful for the short glossary at the front of the novel, although after reading about a third of Fire Country I found that I didn't need to refer to it anymore. Readers who enjoyed Blood Red Road by Moira Young or Riddley Walker by Russell Hoban will absolutely love this book.
Full Disclosure: I received this book for free from the author.