The Columbia Plateau, a vast intermontane region nestled between the formidable Cascade Mountains to the west and the rugged Rocky Mountains to the east, encompasses a significant portion of present-day Washington, Oregon, Idaho, British Columbia, and Western Montana. This expansive area, culturally defined as the Plateau Culture Area, stretches from the Fraser River in the north, marking its northern boundary, to the Blue Mountains in the south, defining its southern extent. Characterized by its semi-arid climate, the Columbia Plateau presents a diverse landscape, ranging from arid steppes to mountainous terrains adorned with pine forests at higher elevations. The lifeblood of this region is the Columbia River, which, along with its tributaries, drains the area, shaping its ecology and influencing the patterns of human settlement for millennia.
A Land of Contrasts: Geography and Environment
While the stereotypical image of the Columbia Plateau is dominated by the dry sagebrush-Juniper steppe, interspersed with pockets of pine forests clinging to the elevated regions, the reality is more nuanced. The northern reaches of the Plateau Culture Area experience a distinctly different climate, marked by a temperate rainforest characterized by significantly higher precipitation levels. This variation underscores the diverse ecological niches present within the Plateau, supporting a wide array of flora and fauna. Furthermore, at the headwaters of the Columbia River in British Columbia, the terrain transforms into a dramatic landscape carved by steep mountain ranges, their valleys cradling long, narrow lakes. These geographical features have profoundly shaped the lives of the indigenous peoples who have called the Plateau home for thousands of years, dictating their subsistence strategies, settlement patterns, and cultural adaptations.
The Plateau People: Adapting to a Changing World
Archaeological research has divided the prehistory of the Plateau into three broad periods: Early (before 6000 BCE), Middle (6000 to 2000 BCE), and Late (2000 BCE to 1720 CE). This article will focus on the Late-Early Subperiod (2000 BCE to 500 BCE). According to James Chatters and David Pokotylo in the Handbook of North American Indians, the cultural adaptations of the Plateau peoples over the past 4,000 years have centered around the "mass harvest and long-term storage of three key resource groups: fish (usually anadromous salmonids), edible roots, and large ungulates." This reliance on a limited number of staple resources necessitated sophisticated strategies for procurement, processing, and preservation.
Around 2500 BCE, regional temperatures began to decrease, leading to glacial advances and a decline in the temperature of the Columbia River. By 2000 BCE, the Indian people inhabiting the Plateau were adapting to these climatic changes through storage-dependent collector activities. This shift towards increased reliance on stored resources may have contributed to the emergence of small villages in certain areas, indicating a move towards more sedentary lifestyles.
Key Developments in the Late-Early Subperiod
The period between 2000 BCE and 500 BCE witnessed a series of significant developments in the Columbia Plateau, shaping the cultural landscape and setting the stage for future transformations.
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2000 BCE: The Indian people began utilizing Dagger Falls on the Middle Fork of the Salmon River in present-day Idaho as a salmon spearing station. This highlights the importance of salmon as a key food source and the strategic locations chosen for its harvest. Around this time, the Alpowa site in present-day Chief Timothy State Park was also occupied.
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1600 BCE: At Kettle Falls, Washington, there was a notable increase in population, marking the beginning of the Skitak period. This population growth likely reflects an increased efficiency in resource utilization or a period of relative environmental stability.
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1500 BCE: The Early Riverine phase commenced, characterized by the widespread adoption of pit house villages. As archaeologist James Keyser notes in his book Indian Rock Art of the Columbia Plateau, roots, salmon, and shellfish became the primary food sources for Columbia Plateau groups during this time. Long-distance trade also intensified, and wood- and bone-working gained prominence as important crafts. This period also saw an influx of refugees from the retreating boreal forests to the north, bringing with them new cultural elements such as stone pipes, copper objects, stone carvings, effigy figurines, and the practice of burial mounds. In southeastern British Columbia and northwestern Montana, the Inissimi Complex began, distinguished by Inissimi stone points with a distinctive expanding stem, convex base, pronounced shoulders, and excurvate blade edges. In the Kalispell Valley of Washington, Indian people began to more intensively utilize camas, a bulbed plant used for food, and fishing became increasingly important. Additionally, Indian people in Idaho began year-round occupation of the Middle Salmon River canyon area, and the hunting of buffalo and mountain sheep increased.
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Shuswap Horizon: The Plateau area of British Columbia entered the archaeological period known as the Shuswap Horizon, a period characterized by cold, wet weather. According to Mike Rousseau, this period saw the establishment of "small, moderately mobile bands" who established "winter residential base camps on valley bottoms where food and material resources were abundant and varied." Terrence Godin adds that the Shuswap Horizon "signifies the first regular, widespread use of semi-subterranean winter pithouses on the Canadian Plateau." These houses were relatively large, averaging nearly 11 meters in diameter and reaching up to 16 meters in some cases, and were circular to oval in shape with flat-bottomed, rectangular floors. The Shuswap people utilized a wide range of resources, including elk, deer, mountain sheep, black bear, small mammals, freshwater mussels, salmon, trout, and birds, but did not rely heavily on plant resources. Their projectile points were generally lanceolate and/or triangular, likely used on thrusting spears or atlatl darts.
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1000 BCE: Hunting became more important along the Middle Snake River in Idaho. Indian people began using fire to manage the landscape, burning large areas to encourage the growth of good deer forage and to improve oak groves for acorns. In the mountain areas of northern Oregon and southern Washington, fire was used to maintain huckleberry patches. The Kootenai people were hunting mountain sheep high in the mountains of what is now Glacier National Park and quarrying chert for stone tools near Bowman Creek.
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800 BCE: The Takumakst period began at Kettle Falls, Washington, associated with Salish people. Material culture included steatite tubular pipes with thin, flaring bowls. People lived in pit houses dug one to two meters deep, cooked with earth ovens, and used pits for storing food.
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625 BCE: People in southeastern Oregon used pole-and-thatch huts or windscreens, described by Luther Cressman as circular frameworks of paired vertical willow branches covered with horizontally laid bundles of grass attached with willow pins and shingled with vertically placed bundles of grass anchored by rock slabs.
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500 BCE: Villages in the Plateau area of Washington and Idaho grew larger, some with as many as 100 pit houses, although the pit houses tended to be somewhat smaller than previously. These larger villages were located on rivers such as at Kettle Falls in Washington and in the Hells Canyon area of Idaho. The Harder phase began to replace the Tucannon phase along the lower Snake River in eastern Washington, with people living in fairly large (20 to 40 feet diameter) pit houses and subsisting on hunting and fishing. Mountain sheep were hunted, and dogs were domesticated. The Nez Perce occupied a number of villages in the southeastern Plateau area, though most settlements were small, containing from one to three structures. At this time, the people intensified their hunting of buffalo, which were found in great numbers in the area. In the Kalispell Valley of Washington, the use of camas decreased due to drought damage to the moist meadows, and the Indian people of this area began to use fire as a tool to increase food production in the higher elevations.
Conclusion: A Foundation for the Future
The period from 2000 BCE to 500 BCE was a time of significant adaptation and innovation for the people of the Columbia Plateau. They responded to changing climatic conditions by developing sophisticated storage techniques, adapting their hunting and gathering strategies, and refining their technologies. The emergence of larger villages and the intensification of trade networks suggest a growing complexity in social organization and intergroup relations. By 500 BCE, the foundations were laid for the cultural patterns that would characterize the Plateau for centuries to come, setting the stage for the arrival of horses, European trade goods, and the profound transformations that would reshape the region in the centuries that followed. The legacy of the early inhabitants of the Columbia Plateau endures, providing valuable insights into the resilience and adaptability of human societies in the face of environmental change.