Paleo-Indian – 10,000 B.C.
Paleo-Indian hunters crossed the Tucson Basin in search of mammoths and other now-extinct large mammals at the end of the Ice Age.

Archaic – 3,000 B.C.
Groups of hunter-gatherers camped on the banks of the Santa Cruz River during their movements around the Tucson Basin.

Early Agriculture – 1,200 B.C.
Farmers living in early villages along the Santa Cruz made the first true irrigation canals in North America. They grew beans and possibly cotton in addition to maize, and developed trade connections with distant parts of the Southwest, California, and northern Mexico to acquire volcanic glass (obsidian) for making dart points and seashells for making jewelry. In 800 B.C. the first ceremonial buildings in the Southwest were constructed in villages along the Santa Cruz River. Earlier than in other areas of the Southwest, the bow-and-arrow began to be used in southern Arizona alongside the older spear thrower and dart.

Early Ceramic – A.D. 100
New types of architecture, pottery, and burial practices suddenly appeared in the Tucson Basin, perhaps representing the arrival of a new cultural group.

Hohokam – 1000
Villages spread out along expanded canal systems. In 1400 the Hohokam culture of southern Arizona collapsed after a population decline related to a series of disastrous flood in the Phoenix basin that may have destroyed most canal systems.

Historic – 1691
The historic period began as Father Kino, the first European to visit the Santa Cruz Valley, found villages of Piman-speakers at Bac and (the next year) Chuk-son—where the San Xavier and San Agustin missions were later established.

Spanish – 1770

Although Tucson celebrates its birthday on the day that the Tucson Presidio was founded, the San Agustin Mission and the adjacent O’odham village were already in place. The mission was founded in the early 1770’s at the foot of Sentinel Peak (“A” mountain) and would be part of the Tucson community for the next 75 years. In 1800 construction of the San Agustin Mission convento began. It was used as an administrative building, dormitory, and school for the San Augustin Mission.
As Mexico gained independence from Spain in the Mexican Revolution of 1821, times were difficult in Tucson. Conflicts with various Apache groups took a great toll on the village. In response to the conflicts of the mid-19th century, the Tucson Presidio was expanded to better protect the community.

Mexican – 1854
The 1854 Gadsden Purchase of the territory that is now Arizona and New Mexico bought Tucson and its surroundings into the American territorial system. Life began to change as Americans from the eastern United States moved to Tucson. Many people opened mercantile businesses, while others developed ranches and mines.

Territorial – 1880
The arrival of the Southern Pacific Railroad allowed for rapid settlement of the Tucson basin. “Progress” arrived quickly with the telephone, electricity, and the central water system. In the mid-1880’s, the Santa Cruz River became entrenched after an ill-fated irrigation scheme failed. Irrigation canals were no longer able to draw water from the river, and many farmers were no longer able to grow crops. Tucson now relied upon wells to draw water from an underground aquifer.

Arizona Statehood – 1912
By 1912, life in Tucson changed dramatically. Over the course of a few years, the river rapidly cut down over 10 feet as far south as the Mission of San Xavier.

Modern – 1950
During the 1950’s Tucson began using the base of “A” mountain as a landfill. In 1999
The Rio Nuevo Cultural District was created. People have been living in the Tucson basin for the past 12,000 years. By creating the Rio Nuevo District, Tucson has elected to embrace the past as part of our shared cultural heritage.