According to H. H. Bancroft, Dunn was a native of Maine who arrived in California on a whaler in 1846 and went to the Sonoma area, where he was recruited for the Second Relief. As a result of his participation in the Donner rescue, Dunn lost some toes to frostbite. In later years He went to southern California where he got into trouble: he joined a gang of desperados and was tried twice for murder. In 1857 Dunn went to Arizona, where he died several years later.
New Light on the Donner Party, Kristin Johnson
Ordeal By Hunger, George Stewart