Which states define the core geographic range of *Crotalus molossus*?

Arizona, New Mexico, and Texas

The distribution of the black-tailed rattlesnake is centered within the American Southwest, extending into northern Mexican territories. The core range explicitly covers several prominent Southwestern states, specifically including Arizona, New Mexico, and Texas. This broad geographical spread contributes to their ability to adapt to various environments, ranging from arid deserts and dry grasslands to more rugged, rocky canyon systems. Their presence across these states necessitates an understanding of their habitat requirements, which include areas where rocky outcrops and dense ground cover are prevalent features of the local ecosystem.