Norman Maclean is the narrator and protagonist of this semi-autobiographical story, which is based on his own family and his childhood and young adulthood in Montana. His close relationships with his parents, the Reverend and Mrs. Maclean, and his brother Paul, are expressed through the family ethos of fly fishing and love for nature. The pristine Montana landscape, along with the fly fishing skills imparted to the brothers by their father, make fly fishing is a spiritual experience. Norman loves fishing, but his brother Paul is a master at it.

Taking after his father, Norman is a serious and thoughtful person. His Scottish heritage, his growing up in Montana, and his work for the U.S. Forest Service ensure that he is self-sufficient and tough. While their father is a minister, both Norman and Paul follow their own paths in life. Norman is married to Jessie, who is also of Scottish heritage, and they live with her parents during the summer of 1937, when most of the story takes place.

Norman feels responsible for his brother, as Paul sinks into alcoholism and accumulates gambling debts. Unable to figure out how to help him, even as Paul rejects the notion that he needs help, Norman is shattered, but not shocked, when Paul dies in a drunken brawl.