Drymarchon melanurus is a large, non-constricting snake in the Colubridae found on the western Pacific coast of Mexico from Nayarit north to Sonora (Rorabaugh and Lemos-E 2019). Villa et al. (2015) discussed its western, eastern, and northern distributional limits in Sonora. The northernmost record was at El Carrizoso (29.516°N 109.150°W; Fig. 1) in the Municipality of Nácori Chico on the Río Áros near the junction with the Río Bavispe where the Río Yaqui proper begins. This is the northern edge of the Northern Jaguar Reserve herpetofauna area (Rorabaugh et al. 2011).
Here we present seven additional observations of D. melanurus that further define its northern distibutional limits in Sonora.
