The Mississippi river runs through in the background of the novel. For example, Nick and Amy’s house lies directly on the Mississippi river. Hannibal, a city on the Mississippi, also figures prominently in the treasure hunt and in Nick’s childhood and teenage years. As the home of Mark Twain, author of The Adventures of Huckleberry Finn, Hannibal is a tourist attraction, and Nick worked there as Huck Finn as a teenager. Amy is also symbolically tied to Huck Finn when she fakes her own death, just as Huck does in Twain’s novel. Amy also threatens to send Nick “up the river,” a symbol for prison, for her murder. The river therefore symbolizes the inability to escape.

Amy’s anniversary treasure hunt symbolizes the reality of her marriage to Nick. On the surface, it appears to be a loving, romantic gesture that celebrates another year of marriage, just as Nick and Amy pretend that they have a happy marriage. Underneath, however, the treasure hunt symbolizes Amy’s rage that Nick doesn’t love her or “get” her enough.

Every year, Nick fails to solve the clues, which are typically based around details of the past year from Amy’s perspective: things Amy loved, places Amy visited.