The Big Hatchet Mountains are an 18 mi (29 km) long, mountain range in southeast Hidalgo County, New Mexico, adjacent the northern border of Chihuahua state, Mexico. The range lies just south of a westerly excursion of the Continental Divide of the Americas; it lies on the eastern perimeter of the extensive, narrow, and north–south Playas Valley, and is the center range of three mostly arid, low to moderate-elevation ranges that lie on the valley's east perimeter. The mountain range lies in the extreme northwest of the Chihuahuan Desert.