Eli is the relentless and imposing patriarch of the McCullough family. Born on the day Texas becomes an independent republic, he experiences tragedy early when a Comanche raiding party attacks his family. Taken captive and raised by Chief Toshaway of the Kotsoteka band, Eli adopts their survival skills and warrior culture. He eventually returns to white American society, where he applies his hardened frontier instincts to build a vast cattle empire, prioritizing strength over sentiment.

Peter is Eli's youngest and least favored son. He stands apart from his father's ruthless nature due to his deep sentimentality and moral conscience. Living on the family ranch, Peter observes the violent conflicts between white settlers and the Tejano population with profound guilt. He feels a strong kinship with his neighbor Pedro Garcia and questions the aggressive tactics his family uses to secure their wealth.

Jeannie is Eli's great-granddaughter. She grows up listening to stories of Eli's frontier exploits and prefers riding horses and working the ranch over fulfilling conservative expectations for young women. After a brief, unhappy period at a Connecticut boarding school, she returns to Texas. Recognizing the declining value of cattle, she takes charge of the family business to shift their focus to the booming oil industry.

Ulises is a young Mexican immigrant who crosses the border to work as a cattle wrangler on the McCullough ranch. Raising funds for his family back home, he lives with the constant fear of deportation. He secretly researches his bloodline, hoping to find a place where he belongs and contemplating how to present his heritage to Jeannie McCullough.

Toshaway is the chief of the Kotsoteka Comanche band. After capturing Eli, he prevents the other raiders from killing the boy and instead takes him under his wing. He teaches Eli the history of the Comanche people and the physical skills required to survive on the plains, demanding loyalty to the community above all else.

María is the eldest daughter of the Tejano patriarch Pedro Garcia. Following a devastating attack on her home, she becomes the sole survivor of her immediate family. She carries immense grief and righteous anger, directly challenging the false narratives created by the local white landowners while seeking refuge.

Phineas is Peter's older brother. He inherits Eli's pragmatic and hardened approach to business, showing little patience for Peter's moral dilemmas. Operating the Railroad Commission, he understands the shifting economy and plots to move the family's wealth into the oil industry to maintain their power.

Charles is Peter's son and Jeannie's father. He embraces the violent legacy of his grandfather Eli, readily participating in vigilante actions against neighboring families. He remains stubbornly devoted to the cattle business, lacking the foresight to see its economic decline.

Sally is Peter's estranged wife. She despises the violence of the frontier but equally dislikes the local Tejano population. She prefers the refined environment of Dallas and frequently pushes Peter to abandon his moral crusades to protect their social and financial standing.

Pedro is a Tejano rancher and the patriarch of the Garcia family. Despite the rising racial tensions and border conflicts, he holds onto his ancestral land out of a deep romantic attachment. He shares a quiet friendship with Peter McCullough until false accusations place his entire family in mortal danger.

Hank is an oil driller introduced to Jeannie by Phineas. He brings technical expertise to the McCullough property to build their first oil rig. While he proves to be a capable business partner, his traditional views on gender often clash with Jeannie's ambition to be directly involved in the field.

Judge Black is a wealthy and influential resident of Austin who takes Eli in after he is ransomed from the Comanche. He encourages Eli to attend school and attempts to smooth out the young man's rough frontier edges to help him assimilate back into white society.

Madeline is Judge Black's daughter. Raised in affluence, she finds herself drawn to Eli's unconventional background and wild nature, initiating a relationship that challenges her father's hopes for a respectable match.

Martin is Eli's older brother. Unlike Eli, Martin is sensitive, bookish, and physically unprepared for the dangers of the frontier. His inability to adapt to captivity highlights the harsh survival requirements of the Comanche lifestyle.

Born Ingrid Goetz, Yellow Hair is a German captive held by the Kotsoteka band. She endures severe trauma and abuse during her captivity, relying on Eli for moments of solidarity before they are eventually returned to Austin.

Prairie Flower is a young woman in the Kotsoteka Comanche band. She engages in a courtship with Eli, helping him understand the complex social and marital customs of the group while offering him much-needed companionship.