The good: I learned a ton about wildfires and wildfire survival. The book itself tends a bit towards the infodump, but the information is generally so interesting that this is not too problematic. Barr herself has worked as a seasonal park ranger, later a full park ranger, and she clearly knows what she is talking about. I love books where a specialist uses fiction as a means to teach in an enjoyable way, and Barr's books always fall under this category.
The bad: As usual in Barr's books, I had real difficulty warming to or even differentiating the characters. Part of the reason for this, I think, is the style: Barr uses dialogue more sparingly than perhaps any other contemporary author I can think of. Pages and pages go by uninterrupted by more than an occasional single word or sentence from the characters. Part of this is due to the wilderness survival setting, part to what seems like a set of atypically terse personalities. However, it means that most of the personalities are of the show-rather-than-tell variety, which in turn makes the whole mystery, already weak, a little more futile. I also must admit that I've never warmed to Anna Pigeon, the protagonist. Most of my repulsion comes from a previous book, in which Anna apparently leaves a murderer to die a horrific death of exposure, and the impression I got of her there is not surmounted by an otherwise weakly delineated personality.
The ugly: speaking of awful deaths, all the characters that I warmed to, and I mean all, died absolutely horrific, nightmarish deaths, and the end of the book left me depressed.