Darwin's fox (Pseudalopex fulvipes) is known to survive only on Chiloé Island off the coast of southern Chile and in Nahuelbuta National Park, 600 km to the north in mainland Chile. The Valdivian coastal forest, in which the Darwin's fox lives, historically spanned from Nahuelbuta National Park southward past Chiloé Island on the mainland. Furthermore, the forest on Chiloé Island was connected to the mainland forest by a land bridge for much of the Pleistocene. Thus, the distribution of Valdivian forest suggests that the historic range of Darwin's fox may have been much larger. We searched the remnant pockets of coastal forest on mainland Chile using live traps, non-invasive techniques and interviews to look for new populations of the critically endangered Darwin's fox. Although no Darwin's fox was captured, evidence of a new population near Punta Chanchán was found.