Task: Question Generation
Input (English): Passage: 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. The Pueblo Alto road network functioned between 1050 and 1140. It facilitated access to watering holes, terraced farming areas, and enabled interaction between Pueblo Alto and great houses like Pueblo Bonito and Chetro Ketl. It also led to a community along Escavada Wash. It may have served an important function in the transport of household goods, construction timber, and people throughout the San Juan Basin. Several road segments appear to be related to a row of Chetro Ketl's exterior rooms, which are thought to have been community storage space.In 1982 Robert Powers theorized that the road network "suggests an intercommunity organization and settlement system of regional extent". Because "Chaco Canyon is the convergence point of all presently documented extra-canyon roads", the area may represent a locus of regional control, or "the apex of the hierarchical system". Powers believes that great houses like Chetro Ketl were involved in civic coordination between the canyon sites and outlying communities. In 1993 David R. Wilcox proposed that a state-level society developed at Chaco, with an administrative center at Pueblo Bonito or Chetro Ketl. In a 2003 study of Chacoan artifacts, Frances Joan Mathien stated that the number of warrior-class individuals that would have been needed to support such a state – Wilcox estimated 500–1,000 – precludes his theory, and Wilcox is assuming a "greater Chacoan organizational complexity than any other scholar to date".Lekson developed a theory called the Chaco Meridian, which is based on architectural similarities between the Ancestral Puebloan sites at Aztec Ruins and Chaco Canyon, and Paquime at Casas Grandes in northern Mexico. He believes the sites were intentionally located on the same approximate line of longitude (107°57'25"), and this indicates a ceremonial connection between them. The Great North Road roughly follows the Chaco Meridian, and many of the ancient roads in the area appear to follow it towards key sites in the basin.
Output (English): What do many of the ancient roads appear to follow towards key sites in the basin?