The central characters in the novel are Julie and the wolves—comprising four adults and five pups—that accompany her on the tundra. Her father, Kapugen, mostly appears in her thoughts; throughout much of the narrative, she believes he is deceased. Other human characters include Daniel, the mentally disabled boy she is married to, and her stepmother, Martha—both of whom play minor roles as she leaves them behind.

Julie is a thirteen-year-old Eskimo girl. Her mother passed away when she was very young, and her father, Kapugen, devastated by grief, took her away from the village into the wilderness. There, he taught her the traditional Eskimo way of life. These lessons become crucial for Julie's survival on the tundra. She is patient, intelligent, observant, and self-sufficient. Despite her fear of being lost, she manages to control her anxiety and carefully manages her resources, both material and emotional.

Amaroq, whose name means "wolf" in the Eskimo language, is a majestic black wolf and the leader of the pack that Julie befriends. Brave and protective of his family, Amaroq becomes an almost surrogate father figure in Julie's mind. The other adult wolves include Amaroq's beautiful mate Silver, who is loving and respectful; Nails, a gray wolf; and Jello, considered the villain of the story and the lowest-ranking member of the pack. Jello takes care of the pups while the other adults hunt and is the last to eat when they return. Eventually, he is exiled and becomes dangerous as a loner, attacking Julie's camp and then Julie herself for her food.

He communicated with her not through words, but with his ears, eyes, and lips; and even praised her with a wag of his tail.
The five pups are playful and childlike in their behavior. Kapu, named after Kapugen, is their leader and Julie's favorite. He is fearless and smart, eventually becoming the pack's leader when Amaroq is killed by hunters. Kapu is the first wolf with whom Julie forms a friendly bond.

Julie of the Wolves is rich with details about wolf behavior and the natural history of the tundra. Although Julie is untrained, she observes her surroundings with the keen eye of a scientist. Her experiences and observations lend credibility to the book's major theme—that humans are just a small part of a vast ecological system. Failing to acknowledge humanity's connection with nature is portrayed as dangerous and destructive; litter, airplanes, guns, oil rigs, and modern gadgets represent the imposition of human will on the natural world.

The contrast between civilization and nature becomes evident when Julie gets lost on the tundra. However, her perspective shifts when she arrives in Kangik and discovers that Kapugen, whom she envisioned as embodying the pure Eskimo ideal, has integrated modern practices. She learns that he even hunts wolves using an airplane, suggesting that Kapugen himself might have killed Amaroq.

Julie is troubled by these compromises and by her father's claim that the traditional ways are fading. She resists his notion that achieving perfect harmony between humans and nature is no longer feasible. Yet, by the book's conclusion, Julie understands that she too must adapt to survive in a new kind of wilderness—one defined by an ecologically conscious modern society.