Sylvia, a 9-year-old girl, is driving her cow home through the woodlands of the Maine countryside. She worries about being late because her mischievous cow, Mistress Moolly, hid from her, but her grandmother, Mrs. Tilley, understands how much Sylvia enjoys exploring the woods while caring for the cow. Sylvia feels so much excitement and wonder in the country, a contrast to the first eight years of her life, where she felt stifled and withered living in a manufacturing town.
A whistle disturbs the evening’s peace, and Sylvia is frightened when a stranger approaches her. The hunter explains that he became lost while searching for birds in the woods and asks if he could stay the night at her house. Sylvia is hesitant, still shy around the stranger, but when they return home, Mrs. Tilley welcomes the hunter inside. At dinner, Mrs. Tilley reveals that her son, Dan, is an explorer who always loved nature and now lives out in California (although they have lost touch and he may be dead). She says that Sylvia is like Dan, exploring her natural environment and making friends with all the wild birds. When the hunter hears this, he reveals that he collects rare birds by shooting and stuffing them and is currently searching the countryside for the rare and beautiful white heron. If Sylvia will help him find the heron, he says, he will give her ten dollars.
The next day, the hunter and Sylvia explore the woods in search of the bird. Sylvia begins to warm up to the hunter, finding him to be friendly and very knowledgeable about birds. She begins to feel hints of love for him, despite that fact that she is horrified by his killing of birds. They do not find the elusive heron, but they drive the cow back home together.
When loggers were chopping down the forest years ago, they left one tree: an old pine-tree that is now the tallest in the forest. Sylvia knows that if she climbs this tree, she will be able to see all the way to the ocean and she may be able to locate the heron’s nest. So excited by this thought that she cannot sleep, she leaves the house in darkness while Mrs. Tilley and the hunter are still asleep.
Sylvia climbs an oak tree in order to reach the shortest branches of the old pine tree. Though she climbs with difficulty, she perceives that the pine tree is helping her on her mission to find the heron, loving her for her brave spirit. Feeling tired yet triumphant, Sylvia finally reaches the top. She feels wonder at the beautiful aerial view of the countryside, and her excitement swells as she spots the heron flying up in the sky. She marvels at the heron and seems to adopt the heron’s perspective, as if they share one mind. She climbs down still thinking about how she will tell the hunter about the heron’s location and how he will react.
Back home, Mrs. Tilley has noticed Sylvia’s absence and is calling out for her granddaughter. Sylvia arrives back at the house, pale and with her clothes tattered and covered in pine pitch. She cannot speak to either the hunter or her grandmother, though the hunter offers to make her rich for helping him find the heron. She questions why she would keep the secret of the bird’s location when he offers her a human connection to the rest of the world. But she recalls the glorious moment she shared with the bird and decides she cannot allow the hunter to kill it.
Sometime later, Sylvia still hears the haunting echo of the hunter’s whistle and remembers the love and loyalty she felt for him. She forgets the sadness she felt when she watched him shoot birds and instead wonders if the friendship she has with the wild birds can replace the human companionship she could have had with him. The narrator wills the nature around Sylvia to come and comfort her with all the gifts the natural world has to offer.