which the expedition crossed the Rio Mancos on its way to California from Old Mexico. 19th and 20th century The Old Spanish Trail trade route passed through the area of Mancos from 1829 into the 1850s. Part of the original Ute Reservation in 1868, Mancos was part of the San Juan Cession of 1873, and cattle ranchers began settling the Mancos Valley in the 1870s, providing cattle to the mining camps of the San Juan and La Plata ranges. Today, the boundary of the Ute Mountain Indian Reservation is located some south of town. At the time it was founded, Mancos served as the primary commercial trading center for eastern Montezuma County, rivaling the town of Dolores to the northwest. At that time, Cortez, now the county seat, was barely a bend in the wagon trail. In the 1890s, Mancos was platted and built as a stop along the Rio Grande Southern Railroad built by Otto Mears - Colorado's southwestern railroad pathfinder, connecting Durango to the east and the Telluride mining districts to the north, via Dolores. Ranchers in the Mancos Valley continued to provide beef, timber, and other agricultural products to the mining camps. Following this, Latter-day Saints colonists moved into the area and established farms and small communities such as Weber and Cherry Creek. Local farmers and ranchers began constructing irrigation canals to bring water from the Mancos River to cropland and pasture in various parts of the Mancos Valley in the late 1870s and 1880s, and by the beginning of the 20th century a large network of irrigation ditches and laterals was operating and continues to operate (with improvements) today. In the mid-2000s, a large project, the Mancos Valley Salinity Control Project, was funded by various sources, including the US Bureau of Reclamation, the Natural Resources Conservation Service, and local irrigation and water companies and districts. The project, nearly complete in 2010, includes replacing many open irrigation ditches with piping to conserve water and prevent salt contamination from infiltration and evaporation of irrigation water. Many of the original irrigation ditches have been determined to be eligible for the National Register of Historic Places, together with various archeological sites. Incorporated in 1894, Mancos town government quickly asserted itself, banning fast riding and driving (of wagons) in town the next year, as well as building boardwalks. A water system and electrical system were constructed in 1904, followed by a