The Animas Valley is a lengthy and narrow, north-south 85-mi (137 km) long, valley located in western Hidalgo County, New Mexico in the Bootheel Region; the extreme south of the valley lies in Sonora-Chihuahua, in the extreme northwest of the Chihuahuan Desert, the large desert region of the north-central Mexican Plateau and the Rio Grande valley and river system.The Continental Divide of the Americas forms the valley's eastern border in a series of mountain ranges.