West Doubtful Canyon is a canyon in the Peloncillo Mountains of southeastern Arizona near the New Mexico border, descending into the San Simon Valley in Cochise County. It formed the western half of a mountain passage that nineteenth-century travelers regarded as a single route called Doubtful Canyon. Because nearby water sources and a low north-south divide created a convenient shortcut to the Southern Emigrant Trail, the pass became important for east-west travel. Together with the canyon now usually called Doubtful Canyon, it carried the Butterfield Overland Mail through the Peloncillo Mountains. During the Apache Wars, frequent ambushes by Apache groups gave the route its dangerous and wary reputation.