Naomi is a twenty-year-old widow traveling west toward California with her large family. Married and widowed by the age of nineteen, she actively discards the Caldwell name in favor of her maiden name, maintaining a fierce independence. She spends much of her time drawing portraits of the people she encounters on the trail. Her unconventional behavior and direct communication style often surprise her fellow travelers.

John is a man in his mid-twenties of mixed Pawnee and white heritage, working alongside his father as a mule breeder. He joins his uncle's wagon train as a hired hand and guard for the journey to Fort Kearny. Having spent his early childhood with his Pawnee mother before being sent to live with his white father, John often feels like an outsider. He finds solace in working with animals, particularly his beloved mules.

Winifred is Naomi's mother, a resilient woman undertaking a grueling overland journey while nine months pregnant. She possesses a mystical streak and often experiences vivid, prophetic dreams. She counsels her daughter with a philosophy of rising above hardships that cannot be changed.

Jennie is John's forty-five-year-old stepmother and the wife of John Lowry Senior. When John was brought to their home as an eight-year-old boy, Jennie immediately took him in and treated him well. She taught him how to read using works by Shakespeare and the Bible.

Washakie is the chief of a band of eastern Shoshoni. Like John, he possesses a mixed heritage, though he was raised entirely within his mother's Shoshoni culture. He acts as a calm, confident leader who prioritizes strategic peace and trade for his people.

Grant is the leader of the wagon train out of St. Joseph and the brother of Jennie Lowry. He recruits his nephew John to assist with the livestock and provide security for the initial leg of the journey. He manages forty families in fifty wagons, attempting to keep them safe from trail hazards.

William is the patriarch of the May family. He uproots his wife and children from Springfield, Illinois, seeking land and a better future in California. He relies heavily on the expertise of guides and hands like John to get his large family across the country safely.

Lawrence Caldwell is Naomi's former father-in-law. He harbors resentment toward Naomi for moving past his son's death so quickly and considers her to be Caldwell property. He exhibits intense prejudice against John's mixed heritage, frequently attempting to undermine the younger man's position on the trail.

John's white father is a successful merchant and mule breeder who brought his family to Missouri years prior. Though he maintains a complicated, distant dynamic with his son, he secretly harbors deep affection for him and respects the memory of John's Pawnee mother.

Webb is one of Naomi's younger brothers. He develops a quick attachment to John Lowry and the mules, frequently trailing after him and inviting him to share meals with the May family.

Hanabi is a Shoshoni woman who previously worked as a servant in Jennie Lowry's household. She returned to her people with the help of John's father and eventually married Chief Washakie.

Wolfe is the youngest member of the May family, delivered by Winifred during the wagon train journey. Naomi names him and takes on a deeply maternal role in his care.

Wyatt is one of Naomi's older brothers. He frequently assists with the heavy labor of moving the wagons and helps John track down lost animals on the trail.

Will is another of Naomi's brothers making the trek to California. He spends his free time practicing with a newly acquired bow and arrows.

Warren is Naomi's oldest brother. He drives his own wagon on the journey, traveling alongside his pregnant wife, Abigail.

Mary is John Lowry's Pawnee mother. She raised John until he was eight years old before bringing him to his father's house, passing away shortly after ensuring her son would be cared for.

Daniel is Naomi's deceased first husband. He died just three months after their marriage, prompting Naomi's complicated feelings about her widowhood and her desire to revert to her maiden name.

Lost Woman is Washakie's mother and a respected elder in the Shoshoni band. She offers comfort and spiritual insight to those grieving.

Abigail is Warren's pregnant wife, undertaking the dangerous journey westward alongside the rest of the May family.