The yellow-bellied marmot (Marmota flaviventris) reaches the southern edge of its geographic range in New Mexico, where it is known from the San Juan and Sangre de Cristo Mountains. We provide a synopsis of the geographic range of M. flaviventris in New Mexico and report 5 recent records from the Jemez Mountains, Los Alamos and Sandoval Counties. Of the 5 records from the Jemez Mountains, 3 were obtained at high-elevation sites (>2690 m) during routine fieldwork and while conducting surveys for the American pika (Ochotona princeps), and 2 were from a residential area at relatively low elevation (2204 m) on a finger-mesa in Los Alamos. We evaluate 3 hypotheses for the provenance of the new records and conclude that M. flaviventris has maintained a relictual occurrence in the Jemez Mountains, but that the recent detections were due to (1) increased mammalogy fieldwork at high elevations, digital camera technology, and social media that allowed mammalogists to become aware of observations, and (2) possibly altered behavior by marmots due to impacts of recent widespread wildfire. Because small, isolated populations of marmots are vulnerable to extinction, research is needed to assess the status and trend of marmots in the Jemez Mountains, as well as in adjacent mountain ranges in New Mexico, with emphasis on identifying conservation threats and prospects for long-term persistence in the state.