In April of 1846, Sarah Graves was twenty-one and in love with a young man who played the violin. But she was torn. Her mother, father, and eight siblings were about to disappear over the western horizon forever, bound for California. Sarah could not bear to see them go out of her life, and so days before the planned departure she married the young man with the violin, and the two of them threw their lot in with the rest of Sarah's family. On April 12, they rolled out of the yard of their homestead in three ox-drawn wagons.

Seven months later, after joining a party of emigrants led by George Donner, Sarah and her family arrived at Truckee Lake in the Sierra Nevada Mountains just as the first heavy snows of the season closed the pass ahead of them. After a series of desperate attempts to cross the mountains, the party improvised cabins and slaughtered what remained of their emaciated livestock. By early December they were beginning to starve.

Sarah's father, a Vermonter, was the only member of the party familiar with snowshoes. Under his instruction, fifteen sets of snowshoes were hastily constructed from oxbows and rawhide, and on December 15, Sarah and fourteen other relatively young, healthy people set out for California on foot, hoping to get relief for the others. Over the next thirty-two days they endured almost unfathomable hardships and horrors.

In this gripping narrative, Daniel James Brown takes the reader along on every painful footstep of Sarah's journey. Along the way, he weaves into the story revealing insights garnered from a variety of modern scientific perspectives–psychology, physiology, forensics, and archaeology–producing a tale that is not only spell-binding but richly informative.