In the beginning ...

The first Tucsonans were probably descendants of people who followed herds of large game animals from Siberia across a land bridge in the Bering Strait into Alaska between about 45000 BC and 12000 BC.

Subsequent generations of these Paleo-Indians (ancient ones) gradually spread southward to populate the Americas. (Possible alternative migration starting points, routes and dates are under intense study.)

It's estimated that by about 9000 BC small bands of hunters had reached the Tucson valley. The post-Ice Age climate was cooler and wetter than today's dry Sonoran Desert. Grasslands thrived. The Santa Cruz River, along with the Rillito River, Pantano Creek and Tanque Verde Creek, flowed year-round. The mountains surrounding Tucson had forests of juniper and pine that extended much farther down their slopes than these trees do today.

The hunter-gatherers

Populating this landscape were huge mammoths (13 feet high at the shoulders), large bison, giant beavers, grizzly bears, camels, deer, elk and horses. Besides hunting these animals, the first Tucsonans probably also hunted smaller game and gathered plant food.

No skeletal evidence of these early hunter-gatherers has been found, and they left few traces of habitation. Only a single campsite is known in Southeastern Arizona - near Sierra Vista. They ranged over large areas, lived in small groups of 25 to 30 people, and didn't stay long in one location. Their movements were probably determined by the amount of game, the season and availability of native plants.

Hunters trapped mammoths and other large animals along streams and lakes, and killed them with spears tipped with large, razor-sharp and distinctively grooved spear points called Clovis points, after Clovis, N.M., a center for this Paleo-Indian Clovis culture.

Five deeply buried kill sites, along with Clovis points and other stone tools, have been found among the bones of mammoths and bison in the San Pedro Valley to the east. Archaeologists have yet to find a kill site in Tucson, but have found two Clovis spear points, one along the Santa Cruz River in the southern Tucson valley and another in the northern Tucson valley.

As the effects of the last Ice Age receded, the climate of what is now Southern Arizona continued to warm and dry. Mammoths and other big game animals began to die off, probably because they couldn't adjust to the climate changes, but perhaps because they were killed by their human hunters. By about 7500 BC the large mammals were mostly gone.

The Desert Culture

People of the Tucson valley now hunted smaller game such as rabbits, deer, birds and bighorn sheep at higher altitudes. They stayed in one place longer, supplementing their diet with berries, seeds, nuts and grains. They maintained seasonal migratory patterns but returned to the same place. They lived primarily in the open, but probably built temporary shelters.

The beginning of this Desert Culture is marked by the appearance for the first time of seed-milling equipment in the form of hand-held stone grinding slabs. Porridge and bread were now a part of the diet.

The only habitation site from this period identified so far in the Tucson valley was found in what is now known as Dove Mountain in the southern Tortolita Mountains.

By about 3000 BC the desert people's grinding equipment had evolved to deep basin bottom-stones or metates, small round handstones or manos, mortars and large stone pestles. Tucson-area habitation sites from this period have been discovered in the Catalina Foothills, the Rincon and Santa Rita Mountains, the lower hills of the Tucson Mountains and alongside the Santa Cruz River and its tributaries.

The climate here had stabilized by about 2500 BC, closely resembling the Sonoran Desert climate of today.

The birth of farming

In about 2000 BC corn was introduced to the Tucson valley from Mexico. Agriculture was an important step for people who had previously relied only on hunting and gathering. The desert people planted corn near camps with permanent water supplies. After planting they resumed hunting and gathering native plant foods, returning to harvest the ripened crop.

By 1500 BC these early farmers were building short irrigation canals along the Santa Cruz River. Flood farming during the summer monsoon season was practiced along the banks of the river and its tributaries by at least 800 BC.

Small farming camps had grown into small agricultural settlements by 400 BC. Such sites have been found in the Tucson valley on low terraces overlooking the floodplains of Tucson's waterways and buried deeply in floodplain sediments.

One such settlement was partially excavated on the site of Tucson's first mission, the historic San Agustin Mission, just east of Sentinel Peak. Plant remains recovered from these settlements reveal that the farmers grew maize and eventually beans, squash, cotton and agave.

Excavation of some of these sites has revealed small round or oval pit houses, bell-shaped storage pits, roasting pits, small fire pits, carbonized fragments of corn and human remains. Other artifacts from this period include marine shell beads and small pendants. Small fire-hardened clay human figures and beads have also been found.

Fired figurines, shell jewelry, bell-shaped pits and corn farming all developed in Mexico centuries earlier than in Arizona. Marine shells and some of the other materials used in tools and ornaments were not locally available in the Tucson area, suggesting that early Tucson farmers traded with Mexico. Thus began the long-term influence that Mexico would have on Tucson.

By AD 100, undecorated, unpolished pottery (brownware) was widely used in the Tucson valley as containers or for storage. Reliance on crops continued to increase. Populations grew. Trade in shells, turquoise and obsidian increased along newly developing trade networks.

The next 350 years saw a long developmental sequence that resulted in increasing the scale of the desert farmers' society. By AD 450 people started coming together in more permanent settlements, built more substantial buildings and massive irrigation systems and formalized their games and rituals.

As Arizona's well-known historian Marshall Trimble puts it, "These desert people were the link between the ancient elephant hunters and prehistoric Hohokam."

On StarNet: Read Bob Ring's recent columns at

About this series

This is the first of a six-part series on the history of Tucson. Author Bob Ring aimed to capture the what, when and how of the major events that shaped Tucson's development.

Here's the series schedule.

• Today, Part 1: Tucson's first residents: Hunter-gatherers to farmers

• Part 2: The Hohokam and descendants

• Part 3: Spanish missionaries

• Part 4: The Spanish/Mexican presidio

• Part 5: Tucson in U.S. territory

• Part 6: Tucson in the state of Arizona

E-mail Bob Ring at Thanks to Henry D. Wallace, senior research archaeologist at Desert Archaeology Inc., for answering my questions and reading and commenting on this article. Sources: "Arizona: A Cavalcade of History" (Marshall Trimble, 1989); "Arizona: A History" (Thomas E. Sheridan, 2012); "Cultural History of the Tucson Basin" (J. Homer Thiel and Michael W. Diehl, 2004); "The Hohokam Indians of the Tucson Basin" (Linda M. Gregonis & Karl Reinhard, 1979); "The Hohokam Millennium" (Suzanne K. Fish and Paul R. Fish, 2008); "People Without Pots: Preceramic Archaeology of the Tucson Basin" (Bruce B. Huckell, Ph.D., 1994); "A Thousand Years of Irrigation in Tucson" (Jonathan B. Mabry and Homer Thiel, 1995); The Paleo-Indians.