Cloyd is a 14-year-old half-Ute, half-Navajo teenager who flunks his classes and frequently runs away to roam the canyons of southern Utah. Raised by his grandmother, Cloyd loves the outdoors and seeks meaning by exploring his ancestral lands. He possesses physical agility for free-climbing and a deep yearning to connect with his Native American heritage, leading him to adopt the secret name Lone Bear.

Walter is an elderly rancher living along the Piedra River in southern Colorado. Mourning the recent death of his wife, he has allowed his property to decline and largely lost his daily motivation. Taking Cloyd in for the summer gives him an opportunity to share his knowledge and care for the son he never had, though his old obsession with gold mining still lingers in his mind.

Grandmother is a traditional Ute woman who raised Cloyd on the high desert of White Mesa. She wears clothing influenced by neighboring Navajo culture and provides Cloyd with a deep connection to his ancestral roots. Rather than forcing strict academic discipline, she allows her grandson the freedom to explore the canyons and learn from the natural world.

Blueboy is a spirited blue roan gelding living on Walter's ranch. Initially skittish from a lack of regular riding, Blueboy quickly takes to Cloyd when the boy offers him feed and gentle handling. The strong, capable horse becomes a steady partner during long rides along the river and steep climbs into the high mountains.

The grizzly is a massive, rare brown bear surviving in the high elevations of the San Juan Mountains. Widely believed to be extinct in the region, the creature represents the untamed wilderness. As a member of a species revered by the Ute people, the animal serves as a living symbol of Native American heritage.

Susan is Cloyd's housemother at the Eaglewing group home for Native youths in Durango, Colorado. She recognizes that traditional schooling is failing her young ward, prompting her to seek an alternative environment. Practical and well-intentioned, she drives him to a mountain ranch in hopes the outdoors will provide better structure.

Rusty is a tall, red-headed outfitter who guides big-game hunters into the mountains. Confident and hard-charging, he exhibits a casual disregard for Native American cultural sensitivities. He views the wilderness primarily as a resource for sport, bringing him into direct ideological opposition with Cloyd.

Leeno is Cloyd's biological father, a Navajo man who disappeared shortly after his son's birth. Following a severe car accident four years prior, he has been left completely brain-dead in an Arizona medical facility. His tragic condition forces his son to reevaluate his search for family.