This dataset includes stable hydrogen isotope values of the nonexchangeable hydrogen contained in the outer most secondary feathers of dark-eyed juncos (Junco hyemalis thurberi) collected from the University of California San Diego campus in La Jolla, California in 2014. Hydrogen isotope values in feathers have become a powerful tool for inferring the breeding grounds of a wide variety of avian species. In most of these migratory species, feathers are molted prior to departing the breeding grounds for more overwintering regions to the south. These data were used in tandem with morphological and genetic data for the classification of resident and migrant birds. There are two files in this dataset: 1) A tab delimitated machine readable file (.csv) that represents the data dictionary, and 2) a tab delimited machine readable file (.csv) containing the data.