The final chapter of the book is about Josh, the only living dog among the nine that Paulsen profiles in the book. Josh is old—around 20—and though the author never comes out and says it, we know this dog must have died soon after the book was published. That's what makes the final section of this dog's chapter such a heartbreaker.
The last few lines imagine Josh,
[…] head and tail down slightly, body relaxed but somehow tensed and ready. The Bighorn Mountains wild across the sky above us and Josh trotting up the trail ahead, looking back at me on the horse, to make sure I'm coming. (9.39)
Josh is always a few steps ahead of Paulsen, even as he's nearing his death. It's a sad and beautiful image—Josh guiding and protecting Paulsen as he moves into his life's next adventure.