At 7,750 feet above sea level, and covering almost 300 square miles, Yellowstone Lake, in Wyoming, is North America’s largest high-elevation lake. Because of the numerous archeological sites that ring its 124 mile circumference, archeologist have long sought to understand the lake’s role in the seasonal subsistence and settlement patterns of the region’s many Native American groups. For the past five years, the Montana-Yellowstone Archaeological Project (MYAP) has focused on research from Yellowstone Lake. Researchers from the University of Montana have worked with Yellowstone National Park cultural resources staff to identify and investigate archeological sites around the lake’s shores. The project is focused on defining the role of Yellowstone Lake in the lifeways of Native Americans who lived within the northwestern Great Plains, the northern Rocky Mountains, and the far northeastern edge of the Great Basin.
Using ethnohistoric (information derived from the study of native peoples from a historical and anthropological perspective) and archeological data, researchers are evaluating four key questions about the use of Yellowstone Lake in prehistory:
- Where did Native Americans come from to get to the lake?
- How were the lake and environs subsistence resources used?
- How did the earliest visitors get to the lake’s islands?
- What was the primary mode of travel while at the lake?
A variety of investigations have been carried out to test hypotheses to answer these questions.
Environment and Research
Yellowstone Lake is the heart of the Greater Yellowstone ecosystem, which encompasses nearly 31,000 square miles within northwestern Wyoming, south central Montana, and northeastern Idaho. The lake is bordered by the Absaroka Mountains to the east and the Teton Range to the south.
The Yellowstone River flows into the lake on its southeast corner, and exits about 18 miles to the northeast. Due to variations in glacier behavior and climate change, water levels have fluctuated significantly during the last 13,000 years, resulting in a series of terraces and paleo-shorelines around the lake. The lake contains six islands, but only three of any significant size.
The shores of the lake contain several vegetation zones, including a moist subalpine fir zone and a forested riparian zone, as well as grassy and sagebrush or shrub and grass habitats. Interspersed among the extensive pine forests that enclose the lake, these open meadows and riparian areas are extremely diverse, containing as many as 400 plant species. During 2009, MYAP researchers studying plant resources in the vicinity of the lake identified 52 plant species within a 20 acre meadow on the northwest shore of the lake. Of these, 15 were food sources, 17 were medicinal, and 8 species were known to be spiritually important.
This diversity of plant resources supports more than 60 mammal species, including bison, elk, moose, big horn sheep, deer, antelope, grizzly and black bear, mountain lion, coyote, and wolf. Another seasonally migratory resource in Yellowstone Lake is cutthroat trout, one of only two surviving native cutthroat trout species left in North America.
More than 285 archeological sites have been identified along the shores of the lake and on the islands. Recent excavations at dozens of lake area sites confirm active use of the lake and the area for the last 10,000 years.
Where did Native Americans come from to get to the lake?
Recent ethnographic and archeological studies indicate that a number of historically-known tribes and their ancestors spent extensive time here. The stone tool data suggest that tribal peoples from the north—Blackfeet, Salish; south—Shoshone, Bannock; east—Crow, Shoshone; and west—Nez Perce—visited Yellowstone Lake, probably following routes still used today along the Madison, Yellowstone, Gardiner, and Shoshone rivers.
People camping on the north shore were likely Plains-adapted hunter-gatherers, spending most of their time in the northern Yellowstone Valley and vicinity. Those camping on the east shore of the lake were likely inhabitants of the plains as well, including the hot and dry portions of northwestern Wyoming, such as the Big Horn Basin. Tribal groups on the southeast lakeshore were probably residents of the Jackson Hole area and points south. Groups on the southwest and western shores may have come from the north, south, and west, including the northern Great Basin of eastern Idaho.
The stone tool and ethnohistorical data, therefore, do not support a hypothesis that Yellowstone Lakes was the center of a large territory used by a single group. Rather, the lake and environs were at the crossroads of multiple territories.