In King's novel Medicine River, several characters represent common literary archetypes.

Will's immediate family meets the definitions of the mother figure, absentee father, and explorer archetypes. Will's mother, Rose Harlan, represents the mother figure archetype. Rose raises her two sons alone after being abandoned by her family and the father of her sons. She is caring and protective, and tries to protect her children as much as possible. The novel portrays Rose through flashbacks, as she is deceased.

The archetype of absent father is representative of Will's dad, who abandoned his family and who serves as a source of bitterness and rejection to Will. James, Will's brother, represents the explorer. Deeply interested in his native roots, he consistently travels in order to gain a deeper understanding of his heritage.

Outside of his immediate family, Will's friends and acquaintances also represent several archetypes in literature. Susan Adamson uses Will as a means to leave her marriage, which she kept secret from Will; her lack of morals and use of Will as a means to an end present her as the temptress archetype who uses her lovers to achieve her own end.

Will's best friend, Harlan Bigbear, represents the everyman. Harlan is well-known throughout the community and involves himself in the doings of others; it is Harlan who encourages Will to move forward in life. Harlan is a recognizable, human character that everyone can relate too.

Strong, independent, and successful, Louise Heavyman is a single mother by choice. Her character traits present her as the common archetype of the rebel, due to her non-traditional lifestyle choices. Southwing, Louise's daughter, fulfills the role of the child. She is innocent, and Will becomes a father figure in her life.