Resumen:
Crotalus intermedius Troschel, 1865 is a venomous snake endemic to Mexico, inhabiting high‐ele‐ vation forests and shrublands. This study presents the first formal record of C. intermedius from the State of Mexico and its potential distribution. Only 11.4% of its potential range overlaps with natural protected areas (NPA), with 10.1% in federal NPAs, including our new record from Monte Tláloc within Iztaccíhuatl‐Popocaté‐ petl National Park, and 1.3% in state NPAs. This finding fills a distribution gap in C. intermedius distribution and increases the number of venomous reptile species recorded in the State of Mexico to 16.