The Road is a River, by Nick Cole

In The Old Man and the Wasteland, we meet the Old Man, who survives peril on his trek to Tucson, where he discovers the last refuge of a lone soldier who tried to keep civilization together.  In The Savage Boy, we meet the Boy who, after his soldier/mentor dies, proves himself as a warrior, finds love, and has it all taken away from him.  In The Road is a River, Nick Cole brings their stories together, completing the journey in the third book of the American Wasteland trilogy.

Having moved the people of his village from their desert outpost to the city of Tucson, the Old Man is feeling a little restless.  Everyone is settling in, scavenging what is left from the city, and reestablishing a civilized life.  But the Old Man picks up a radio broadcast from Cheyenne Mountain, the underground bunker in Colorado, where a group of survivors is trapped due to a cave in.  If he takes a tank and picks up a special weapon at a military base, he can come to their rescue.  He and his granddaughter set out on this journey, hoping they can find the fuel they need along the way and face down any dangers they encounter.

Along the way, they meet the Boy and mercifully invite him to join them.  His survival and fighting skills turn out to a boon, and together they make their way to Colorado.  Cole's prose is thoughtful and vibrant.  The ragged crew comes through some close scrapes with danger but Cole doesn't rely on implausible twists or silly plot points.  Though the world has changed, the laws of physics and human nature are still fully intact, and the story is thoroughly realistic and believable.

I will say this, after reading this trilogy: I admit that I approached it with skepticism.  Mad Max and all the sequels and imitators have really turned me off to this sort of post-apocalyptic fiction.  The American Wasteland trilogy definitely shares some traits with the genre, but it stands above with the humanity, plausibility, and thoughtfulness Cole brings to the stories.  So if you are a fan of post-apocalyptic sci-fi, you definitely want to pick this trilogy up.  And even if you're not, the American Wasteland trilogy is worth a read.