O'Dell called Sing Down the Moon an adventure about loyalty. Bright Moming, a young Navaho woman, remains loyal to her family, her homeland, and her people. The book opens with Bright Morning remembering the first time she took her family's sheep onto the mesa at Canyon de Chelly to begin the spring grazing. When a late spring blizzard strikes, she secures the sheep in a grove of trees but becomes frightened and abandons the flock. Although the sheep survive, Bright Morning feels that by leaving, she has betrayed both them and her family. Looking back on the incident a year later and recalling her family's disapproval, Bright Morning understands the importance of loyalty. Her experiences throughout the novel— being captured as a slave, being forced to participate in the Navaho "long walk" into exile from Canyon de Chelly, marrying the recently crippled Tall Boy, and returning with her new husband to the canyon—test and strengthen her loyalty to the people and places that are part of her identity and her integrity.