 A long-distance communication system that used smoke and mirrors existed in the region, and direct lines of sight have been established between Pueblo Alto, Huérfano Mountain in northern New Mexico, and Chimney Rock Pueblo in southern Colorado.Messages could have been relayed between these three points within minutes.On the mesa behind Chaco Canyon is an ancient road that runs north from Chetro Ketl, then northward along the east side of Pueblo Alto before joining with the Great North Road.