Book excerpt: Jean Aspen, daughter of arctic explorer and author Constance Helmericks, began life in the wilderness. Throughout six decades, the natural world has remained central to her. What began as a series of letters to her son, Lucas, when she and her husband Tom set out to search for a different future, evolved over the seasons into a many snapshots of her remarkable life. All those seemingly random threads have woven the tapestry of her journey and the journey of the river flowing by the remote cabin. In Trusting the River, she closes the circle of her mother's books and her own early work, Arctic Daughter.