Because Burrowing Owls (Athene cunicularia) often nest in colonies of prairie dogs (Cynomys sp.), recent declines of Gunnison's prairie dogs (Cynomys gunnisoni) could adversely affect this owl, considered uncommon in northern Arizona. In 2005, we determined the colony size and burrow density of 33 active Gunnison's prairie dog colonies in grasslands of northeastern Arizona. In 2006, we surveyed these colonies to determine the presence and relative abundance of Burrowing Owls, monitored nests to estimate nest success and productivity, and studied habitat characteristics at Burrowing Owl nest burrows. The 33 mapped colonies had a mean colony size of 16.6 ha and mean burrow densities of 57.7 active burrows/ha and 122.9 total burrows/ha. Seventeen nesting pairs of Burrowing Owls were associated with 12 of 33 (36%) prairie dog colonies, producing an average of 1.7 young per nest. Burrowing Owl presence at a prairie dog colony was not related to colony size or burrow density. Occurrence of an owl nest within a prairie dog colony was positively correlated with the mean number of active prairie dog burrows, total burrows, and percent of active burrows within 50 m, and negatively correlated with distance to the nearest active and inactive prairie dog burrow, elevation, and percent slope. Eight of 17 (47%) Burrowing Owl nests were successful, with brood size averaging 5.4 young per successful nest 25–31 days after hatching. Successful nests had fewer active, inactive, and total prairie dog burrows within 50 m than unsuccessful nests, contrary to previous findings. Successful nests also were closer to the nearest road than failed nests.