Mixcoatlus barbouri is a pit viper species endemic to Mexico.

[3] The specific name, barbouri, is in honor of American herpetologist Thomas Barbour.

[6] Mixcoatlus barbouri is found in the highlands of the Sierra Madre del Sur in the state of Guerrero, Mexico.

[2] The preferred habitats of M. barbouri are mountain areas at some 9,000 feet (2,740 m) elevation in rocky pine forests and clearings with bunch grass.

[1] A species is listed as such when the best available evidence indicates that the geographic range, in the form of extent of occurrence, is estimated to be less than 5,000 km² (1,930 mi²), estimates indicate the population is severely fragmented or known to exist at no more than five locations, and a continuing decline has been observed, inferred or projected in the area, extent and/or quality of habitat.