The western lowlands of Colombia, extending south into northern Ecuador west of Andes; the lower slopes and inner valleys of the Colombian Andes, including the western versant of the Eastern Cordillera; and the Caribbean lowlands of Colombia east to the Sierra Nevada de Santa Marta region, continuing through the Departamentos de César and Norte de Santander into the Maracaibo Basin of Venezuela and the northwestern coastal lowlands as far east as Caracas and Estado Miranda.
Holotype: MNHMP 3923 according to Golay et al., 1993, Endogly. Venom. Snakes World 478pp.[164]
Type-locality: Cartagena, Colombia
Five subspecies, namely M. d. dumerilii (Jan, 1858), M. d. antioquiensis Schmidt, 1936, M. d. carinicauda Schmidt, 1936, M. d. colombianus (Griffin, 1916), and M. d. transandinus Schmidt, 1936, were recognized by Roze, 1983 [dated 1982], Mem. Inst. Butantan 46:305-338[321-322], the most recent reviewer. Additionally, Roze, 1989, Am. Mus. Novit. 2932:1-15[7] described a sixth subspecies, M. d. venezuelensis.
