From November 20, 1846 to March 1, 1847, Irish immigrant Patrick Breen, a Donner party member, kept a diary of his ordeal in the mountains. Clinging to survival with his wife Margaret and their seven children, Breen described the harsh winter weather, the leather hides they resorted to eating, and the deaths of their traveling companions.

As spring approached, rescuers made their way to the Donner party's mountain encampment. By March, Breen and his family were safely at Sutter's Fort in California. All seven children and both parents had survived. Baby Isabella, who remembered nothing of the ordeal, lived until 1935, the last survivor of the Donner party.

The Bancroft Library of the University of California, Berkeley, has made page images of the diary available as part of the Online Archive of California. See the digital copy, including transcriptions of the diary, at http://www.oac.cdlib.org/images/ark:/13030/tf10000759.