The novel’s fictional Idaho setting—the Middle Fork of the Garnet River—bears a notable resemblance, in both its formidable rapids and its extreme remoteness, to the real-life Middle Fork of the Salmon River in Idaho. The real Middle Fork flows through the heart of the Frank Church—River of No Return Wilderness, a region defined officially as a “land of steep mountains, deep canyons, and wild rivers” (“Middle Fork Ranger District, Salmon-Challis National Forest.” U.S. Forest Service, 14 May 2026). Spanning nearly 2.4 million acres, it stands as the second-largest designated wilderness area in the lower 48 states.

Because it is surrounded by millions of acres of protected wilderness, the river is extremely remote. This profound isolation serves as a critical plot device in The Last to Drown, ensuring the characters are completely cut off from the outside world when the attacks begin. The introductory epigraph notes, “Once you put in at Boundary Creek, there is no road access for over one hundred miles” (10), closely mirroring the real river’s isolation. The river’s rapids are famously challenging, with classifications ranging from easily navigable Class I to expert-only Class IV, and potentially lethal Class V during high water. The novel’s treacherous “Devil’s Stairs” and “Anvil Falls” reflect the real dangers that make the river both a sought-after adventure and a setting where survival is not guaranteed. Access is strictly controlled through a lottery permit system, limiting the number of people on the water at any time and amplifying the characters’ vulnerability.