Evergreen / Rebecca Rasmussen.

Enhanced descriptions from Syndetics:

From the celebrated author of  The Bird Sisters,  a gorgeously rendered and emotionally charged novel that spans generations, telling the story of two siblings, raised apart, attempting to share a life.

It is 1938 when Eveline, a young bride, follows her husband into the wilderness of Minnesota. Though their cabin is rundown, they have a river full of fish, a garden out back, and a new baby boy named Hux. But when Emil leaves to take care of his sick father, the unthinkable happens: a stranger arrives, and Eveline becomes pregnant. She gives the child away, and while Hux grows up hunting and fishing in the woods with his parents, his sister, Naamah, is raised an orphan. Years later, haunted by the knowledge of this forsaken girl, Hux decides to find his sister and bring her home to the cabin. But Naamah, even wilder than the wilderness that surrounds them, may make it impossible for Hux to ever tame her, to ever make up for all that she, and they, have lost. Set before a backdrop of vanishing forest, this is a luminous novel of love, regret, and hope.