Kya is a resourceful six-year-old girl abandoned by her family to survive alone in the primitive marshes of coastal North Carolina. Labeled the 'Marsh Girl' by the townspeople of Barkley Cove, she faces intense social isolation and educational neglect. To feed herself, she harvests mussels from the mud and trades them for basic necessities. She develops a profound connection to the natural world, relying on her direct observation of animal behavior to understand human interactions and survive in a harsh environment.

Tate is a gentle, thoughtful boy from Barkley Cove who prefers the quiet of the marsh estuaries to the busy town center. The son of a local commercial shrimper, he carries a deep sense of grief over the sudden loss of his mother and sister in a car crash. He serves as an early, rare friendly presence for Kya, understanding her environment without judging her ragged appearance. He shares his love of literature by offering her reading lessons in the woods.

Jake is a World War II veteran and the son of a once-wealthy Asheville cotton family who lost their fortune in the Great Depression. He receives a small military disability pension but spends much of his time away from home on extended drinking binges. His severe physical violence and verbal cruelty drive his wife and four older children away, leaving him alone with his youngest daughter. He occasionally shows brief, confusing moments of paternal behavior before reverting to aggression.

Chase is the handsome, privileged son of wealthy store owners in Barkley Cove. Regarded as a hometown hero and a star athlete, he enjoys absolute high social status in the community. In the narrative's past timeline, he is a confident town boy who explores the edges of the marsh and eventually notices the isolated girl living there, viewing her as an exotic curiosity.

Jumpin' is an older African-American man who operates a bait and gas station on the edge of the marsh. Operating within the strict racial segregation of the 1950s South, he shows quiet generosity to those in need. He recognizes Kya's vulnerable situation early on and establishes a practical trading arrangement to help her secure basic supplies without bruising her pride.

Marie is a former New Orleans resident who married Jake Clark against her wealthy family's wishes. Broken by years of severe domestic violence and isolated in the primitive marsh shack, she reaches a breaking point and leaves her children behind. Her departure serves as the defining traumatic event in Kya's early life, setting the young girl on a path of total self-reliance.

Ed Jackson is the local law enforcement officer in Barkley Cove. He adheres closely to the town's established social hierarchies and harbors traditional prejudices against those who live outside the town limits. When tasked with investigating a high-profile death, he relies heavily on circumstantial physical clues and local diner gossip to build his legal theories.

Mabel is a caring woman from the local African-American community who actively participates in her church's charity efforts. When she learns about a young girl surviving alone in the marsh without a mother, she quietly organizes donations of clothing and supplies. She provides practical maternal guidance from a distance to respect the era's strict social boundaries.

Patti Love is a prominent, affluent woman in Barkley Cove who fiercely protects her family's social standing. As a representative of the town's middle-class elite, she expects deference from those around her. She firmly believes in the absolute goodness of her son and directs the police toward suspects she deems socially inferior or unacceptable.

Pearl is a quintessential Barkley Cove girl whom Kya secretly nicknames 'Alwayswearspearls' due to her exceptionally neat, privileged appearance. She represents the standard of acceptable, middle-class femininity that the town values, standing in sharp contrast to the wilder, unkempt existence of the marsh residents.

Robert Foster is a professional editor located in a city entirely outside the insular world of Barkley Cove. Operating in a broader intellectual sphere, he evaluates work based on its objective quality rather than the family background of the creator. His presence provides a rare, legitimate professional connection to the outside world.

Tom Milton is a highly respected attorney tasked with managing the deeply prejudiced legal environment of Barkley Cove. He brings a calm, methodical approach to the courtroom, relying on strict logic, timelines, and physical evidence to counter the emotional and biased assumptions of the local townspeople.

Scupper is a hardworking commercial shrimper who earns a modest living by harvesting from the sea. Though firmly part of the town's accepted social structure, his daily physical labor connects him closely to the water. He shares a quiet, emotionally supportive home life with his son following the tragic, sudden deaths of his wife and daughter.

Jodie is Kya's older brother and the last of her siblings to remain in the shack before the domestic abuse becomes intolerable. Before eventually fleeing the volatile household himself, he tries to impart basic, life-saving survival advice to his little sister, teaching her to hide deep in the marsh whenever strangers approach their property.

Joe Purdue is the local deputy who assists in the high-profile investigation following the death of a town hero. He is highly pragmatic and distinctly aware of the town's swirling gossip, often bringing rumors, alternative theories, and community chatter directly to the sheriff's attention during their police work.