Lily is a highly resourceful, hard-working woman who grows up on a homestead in the harsh desert southwest. She possesses a natural affinity for breaking horses and managing difficult terrain. Pursuing education and independence, she handles the challenges of the early 20th-century American West by taking on various jobs, from teaching in one-room schoolhouses to managing large ranches. She approaches life with pragmatism and a fierce desire to dictate her own path.

Lily's father is a determined man who manages the family homestead and later the KC Ranch. He frequently develops eccentric money-making schemes, ranging from raising peacocks to breeding dogs, though his primary work involves carriage horses. He teaches Lily essential survival skills, including reading, basic arithmetic, and horseback riding.

Helen is Lily's younger sister. Unlike Lily, Helen is characterized by her physical frailty and reliance on others. She struggles with the harsh demands of the American West and dreams of a more glamorous existence, eventually moving to Los Angeles to pursue a career in motion pictures.

Jim is a steady, capable man who works as a mechanic and later manages massive cattle ranches in Arizona. He maintains a calm, grounded demeanor that provides a solid foundation for his family. He excels at working with livestock and proves to be an equal, respectful partner to Lily.

Rosemary is Lily and Jim's free-spirited daughter who grows up on vast Arizona ranches. She possesses an artistic soul and deeply dislikes seeing animals confined, reflecting her own intense desire for freedom. Her wild nature frequently leads to conflicts with her mother's strict expectations.

Originally from a wealthy background, Lily's mother struggles significantly with the realities of frontier life. She is a deeply religious woman who prefers to stay indoors away from the dirt and labor of the ranch. She views events through a lens of divine will, contrasting sharply with the proactive attitudes of her husband and eldest daughter.

Buster is Lily's older brother. He grows up working on the family's demanding west Texas and New Mexico properties, handling daily ranch duties. He remains tied to the agricultural lifestyle established by their parents.

Little Jim is the second child of Lily and Jim Smith. He grows up on the expansive Arizona ranches alongside his sister, though he adapts differently to their environment. He eventually plays football at Arizona State University and pursues a career as a police officer in Phoenix.

Rex is an adventurous Air Force pilot who takes a strong romantic interest in Rosemary. He is highly charismatic and unbothered by conventions, willing to try new experiences like riding horses or playing poker with Lily. Lily views his grand schemes with suspicion, believing he lacks stability.

Ted is a man Lily meets and becomes romantically involved with during her years working in Chicago. He claims to travel frequently for his job, leaving Lily alone in the city for extended periods of time.

Rooster is a deputy in the rough town of Red Lake, Arizona. After Lily proves her competence by taming a wild mustang, the two become friends. He introduces her to local poker games and horse racing.

Mother Albertina is the Mother Superior at the boarding school Lily attends. Recognizing Lily's academic talents and natural authority, she strongly encourages the young girl to pursue a career in teaching.

Jeannette is the granddaughter of Lily Casey Smith and the author of the narrative. She develops a special, close bond with her grandmother during the early years of her life in Arizona.

Minnie is Lily's roommate and closest friend during her time in Chicago. The two young women explore the bustling city together, sharing the experience of urban independence away from their rural roots.

Fidel is an attractive young Havasupai man who works as a ranch hand for Jim and Lily. He assists visiting school officials by serving as a translator and draws the attention of a teenage Rosemary.

Dorothy is the daughter of a poor tenant farmer who takes up residence on Lily's Father's ranch. She integrates into the Casey family dynamic and eventually marries Lily's older brother, Buster.

Zachary is a struggling tenant farmer who moves onto the KC Ranch. His presence helps generate income for Lily's Father when the property begins falling into disrepair.