River of Doubt by Candace Millard
About Teddy Roosevelt's post-presidency Amazon river discovery voyage. I knew he'd done such but figured it was a "gentleman's tour" complete with rest stops, etc so it wasn't too strenuous yet would make for a good drawing room story later on.
Not at all. Truly a survival story.
While the hero's of the book are largely Kermit, his son, and a Brazilian colonel who were the true brains and muscle, along with the Brazilian grunts, of the expedition, to be in your late 50s and battle it out in the jungle for several months utterly alone and in no contact with civilization is pretty bad-ass. It was a 50-50 on survival of the group.
Excellent read, not overly dramatic.