Archeological Significance of Yellowstone Lake
Yellowstone Lake is considered by many to be the heart of Yellowstone National Park (YNP; figure 1). As North America’s largest, high-elevation natural lake at nearly 8,000 ft. (2,400 m) above sea level, this 20 mile long by 15 mile (32 x 24 km) wide freshwater body of water has played an important role in the lifeways of Great Plains, Great Basin, and Rocky Mountain Native Americans for 11,000 years. As many as ten different tribes likely lived near enough to the lake to exploit its vast resources. The following article is an adapted excerpt from my book, Before Yellowstone: Native American Archaeology in the National Park, published by University of Washington Press in February of 2018.
by Douglas H. MacDonald
I led my University of Montana (UM) archeology crews on five years of archeological research trips (2010-2014) along Yellowstone Lake’s remote southern and eastern shores. We also conducted archeological excavations at the lake’s popular north shore between 2015 and 2017. From our two base camps (Grant Village and Fishing Bridge), our four-person team traveled along the western shore of the lake to the Bridge Bay Marina. Once at the marina, we loaded our equipment and supplies into a motorboat, which dropped us off at the boundary of the no-motor zone on the lake. From there, we transferred our supplies to two canoes and paddled to our backcountry camps. Once at our camp, we set up our tents, loaded the canoes with archeology gear, and paddled to many archeological sites to conduct excavations.
Just as we did, Native American hunter-gatherers traveled up the valleys of the major rivers and creeks to get to the lake. Many of the camps we lived in for our archeology work had been used by Native Americans before the park was created. Native Americans, however, walked to the lake and walked around the lake once they got there. Based on our research, it is unlikely that native communities used boats on the lake; however, the lure of the abundant wild resources lured these hunter-gatherer peoples to its shore.
Because of its high altitude, the lake area averages about 70°F (21°C) in the summer; yet the valleys outside the park can be as much as 20°F (6°C) warmer. Streams that flowed readily in the spring and early summer at the lower elevation settings dry up, as do many of the wild resources. As part of their mobile seasonal settlement pattern, Native Americans from the lower elevations traveled upward, starting in the early spring, venturing to higher elevations during the warmer months not only to escape the heat, but also to follow the animals and ripening plants on which they subsisted.
The flow of the seasons is important in understanding prehistoric human use of Yellowstone Lake. May through October at the lake have average temperatures around or above 50°F (10°C). From November through April, the lake area receives snowfall averaging 20 in. (50 cm) or more per month, with an accumulation of 3 ft. (90 cm) or more. Yellowstone Lake freezes up to 25 in. (63 cm) thick between about early December and early to mid-May. In winter through early spring, Native Americans likely traversed the frozen lake surface to access the islands more easily than they could at other times of year. In the warm months, a variety of game animals migrate upward in elevation to places including Yellowstone Lake, then move down from the lake area to lower elevations in winter. As many as 60 different mammal species live in the vicinity of Yellowstone Lake, including bison, elk, moose, bighorn sheep, deer, antelope, grizzly and black bears, mountain lion, coyote, cougar, bobcat, and wolf. Our archeological research shows that Native Americans hunted all of these large animals while they camped at the lake, with rabbit, deer, bison, elk, and bear being particularly popular prey species.
Another seasonally migratory food source in Yellowstone Lake is Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), one of only two surviving original native cutthroat trout species left in North America. This trout species was probably relatively abundant at the lake prehistorically, especially in spring when the trout runs up the lake’s creeks to spawn. However, as I describe below, fish were not actively used as a food item by tribes that visited the lake.
The shores of Yellowstone Lake contain several vegetative zones, including a subalpine spruce and fir zone, pine woodlands, riverine and marshland habitat, and sagebrush grasslands, all a result of several transitions occurring in the park after deglaciation. Interspersed among the extensive pine forests, there are abundant open meadows and riparian areas that contain an extremely diverse array of plants—as many as 400 different species. The ripening of these plants for food, such as camas bulbs and bitterroot, likely drew people to the lake in spring as well. During one of our archeological field schools at Yellowstone Lake in 2010, two of my students identified 52 different plant species used by early Native Americans in a 20-acre (8-hectare) meadow (Osprey Beach) on the northwest shore of the lake near Lake Lodge (figure 2). Of these 52 plant species, 15 were recognized as food sources, 17 as medicinal, and 8 as spiritually important.
To get to the lake and its variety of wild resources, Native Americans followed the valleys of major creeks and rivers that cut through the mountain passes. The Yellowstone River is the major lake tributary and has two confluences on the lake: one flowing in on the southeast corner and one flowing out about 18 miles (30 km) to the northeast at Fishing Bridge. Among the 40 or so other smaller streams that flow into the lake with headwaters in the Absaroka Range, Clear Creek arrives on the northeastern shore of the lake. Each of these three major waterways—the southern and northern conferences of the Yellowstone River and Clear Creek—were active travel routes in prehistory, along other major lake feeder streams. For example, the Madison River to the west of the lake and the Lewis River to the south were also major regional travel routes used by Native Americans to gain access to the resources of the Yellowstone Plateau.
Archeological Sites at Yellowstone Lake
The first survey for archeological sites in YNP was conducted by Montana State University (MSU), Missoula (now the University of Montana) in the late 1950s and early 1960s. Led by Jacob Hoffman, the first professional archeologist to identify the high density of prehistoric archeological sites at Yellowstone Lake, the original survey identified over 200 archeological sites within YNP. In the early 1960s, Dee Taylor of MSU-Missoula performed additional archeological excavations in the Fishing Bridge area on the north shore of the lake near the Yellowstone River. The National Park Service’s Midwestern Archaeological Research Center and the University of Montana also conducted additional work there in the 1990s and 2000s, respectively. In the early 1990s, the National Park Service (NPS), together with a private archeological consulting firm, Lifeways of Canada, led excavations at the Osprey Beach site and its 9,500-year-old Cody Culture occupations. Between 2009 and 2016, YNP again provided funding for my UM team to complete surveys and tests of archeological sites on the northwest, eastern, and southern shores of Yellowstone Lake. These various studies have identified at least 300 archeological sites along the shores of the lake.
Excavations by the UM team at dozens of sites from 2009 to 2017 confirm active use of the lake since the Clovis period. The UM team found a Clovis projectile point on the south shore of Yellowstone Lake, indicating its use by Native Americans approximately 11,000 years ago. After the first ephemeral visits to Yellowstone Lake by Clovis people, Late Paleoindian Period Cody Culture people increased their use of the lake beginning about 9,500 years ago. The Fishing Bridge site contained an Early Archaic hearth dating nearly 6,000-years-old, which remains the oldest radiocarbon-dated fire pit of any site at the lake. Early Archaic Native Americans used large side-notched projectile points that are often referred to as Mummy Cave points, since several were found at the Mummy Cave site (Wyoming) near the eastern park boundary on the east entrance road. Early Archaic hunter-gatherers sought the cool temperatures and reliable water supply of Yellowstone Lake during the Altithermal, a hot and dry period that prevailed 7,000 years ago. The Altithermal was so hot and dry at lower elevations that the modern form of bison (Bison bison) evolved at the expense of the large herds of the ancient, large-bodied bison (Bison antiquus).
Middle Archaic Native American camps were quite common at Yellowstone Lake as well. In the early 1990s, the NPS excavated several fire pits at two sites in the West Thumb near Arnica Creek, used by Native Americans dating to approximately 4,000 years ago. Here, as well as in Middle Archaic features at the Fishing Bridge Point site, archeologists found several split-base McKean and Oxbow points that are diagnostic of the Middle Archaic period.
The Late Archaic period witnessed a significant increase in Native American use of the lake area between 3,000 and 1,500 years ago, with numerous archeological sites around the lakeshore having fire features and projectile points dating to this time period. A hearth was excavated by my students in 2014 at a site on the Flat Mountain Arm of Yellowstone Lake (figure 3), with a radiocarbon date of the Late Archaic period, approximately 2,000 years ago, and associated with Pelican Lake−type projectile points. Late Archaic Native Americans hunted large herds of bison like those visible today in the park.
Native Americans continued active use of Yellowstone Lake in the most recent Late Prehistoric period (1,500-200 years ago). We excavated the remains of several campfires used by Native Americans near the Fishing Bridge campground and store in 2011, evidence that Native Americans probably utilized Yellowstone Lake around the time of Euro-American contact. For at least 10 millennia, Native Americans used a spear thrower, or atlatl, to hunt. About 1,500 years ago, the bow and arrow was introduced, changing the face of hunting in the Great Plains and Rocky Mountains. Requiring very small arrow points, these points are present at numerous sites around the lake, including a site in the lake’s southeast arm (figure 4). Also at that site, in 2014 UM archeologists found the intact remains of a Late Prehistoric stone circle, or tipi lodge base, beneath a foot of dirt.
In addition to arrow points, sherds of small amounts of Late Prehistoric pottery used by Native Americans were found at the First Blood site in the West Thumb area. NPS archeologist Kenneth Cannon excavated that site in 1992, but most of the pottery was recovered in the late 1950s by Jacob Hoffman. The pottery was produced from local clay tempered with crushed rock, and was used to both cook and store food. This type of pottery is called Intermountain Ware, often associated with archeological sites used by the Shoshone Indians within the past 1,000 years in YNP.
Which Native American Tribes Used Yellowstone Lake?
Was Yellowstone Lake within the territory of one tribe or many? Some archeologists suggest that Yellowstone Lake was at the center of a large territory used by a single group of Native Americans, perhaps the Shoshone or another tribe. Other archeologists suggest that multiple tribes from different regions used the lake.
Peter Nabakov and Lawrence Loendorf conducted extensive research on Native Americans in YNP, much of which can be found in their 2004 book, Restoring a Presence: American Indians and Yellowstone National Park. Their research indicates that diverse groups, including the Shoshone, Bannock, Crow, Blackfeet, Salish, Kiowa, and Nez Perce, utilized the region in late prehistoric times. In particular, the Blackfeet and Crow were thought to have used the northern tier of the lake, while Nabakov and Loendorf suggested that the Eastern (or Wind River) Shoshone mostly used the lake’s southern tier. The Bannock and Nez Perce mostly used the northern tier of the lake as well, with the Nez Perce apparently using the Pelican Creek Valley as a main warm-season bison hunting area. With this approach, it is not reasonable to think that the Shoshone were the exclusive users of present-day YNP, even in later prehistory.
In support of the multi-tribe model of lake use, data collected by my UM archeology teams and others at dozens of lake area sites suggest that a variety of Native American tribes used Yellowstone Lake before European American contact. Based on lithic raw material (stone tool) source locations, it appears that each tribe likely utilized different travel routes to get to Yellowstone Lake, following similar routes that people use today to travel to the park. Except for sites on the southeast shore of the lake, Obsidian Cliff obsidian is common at most lake area sites. Therefore, nearly all the Native American people who utilized the lake (with the possible exception of tribes on the southeastern shore) apparently also traveled to Obsidian Cliff, some 25 miles (40 km) to the northwest of Fishing Bridge, to procure stone for tool manufacture.
Based on stone tool material distributions and ethnographic data, Crow, Blackfeet, Salish, Nez Perce, and, to a lesser extent, Shoshone likely were active on the northern shore of Yellowstone Lake in the recent past. Because of extremely high densities of Obsidian Cliff obsidian and Crescent Hill chert at archeological sites near Fishing Bridge and Steamboat Spring, Native Americans living on the northwestern shore of the lake oriented their travel patterns toward Obsidian Cliff and the Yellowstone River, north of the lake. The low numbers of other types of obsidians from the south indicate infrequent travel and trade with people living south of Yellowstone Lake toward Jackson, Wyoming, and the Snake River Valley. On the eastern lake shore, Native Americans produced tools from Obsidian Cliff obsidian, Absaroka Mountain cherts, and local Park Point obsidian (with a source on the east shore of the lake).
On the southeast lake shore, the southern Yellowstone River and Snake River headwaters were likely origin routes for Shoshone and, perhaps, Crow, Northern Cheyenne, Kiowa, and Arapaho tribes in historic times. These Native American tribes on the southeastern lakeshore may not have traveled often to Obsidian Cliff because it was more than 75 miles (120 km) away, with Jackson, Wyoming, obsidian sources only 30 miles (48 km) away. The low densities of obsidian suggest that these southeastern shore Native Americans likely did not travel to Obsidian Cliff very often because of the long distance to walk around the lake to get to the cliff.
Therefore, the southwestern lakeshore appears to have been somewhat of a multi-use area for Native American tribes from the south, west, and north in late prehistoric times. The West Thumb appears to have seen active use by a variety of tribes, likely including tribes from the south (e.g., Shoshone), the west (e.g., Shoshone and Nez Perce), and the north (e.g., Crow, Blackfeet). Obsidian Cliff obsidian is among the more common obsidians at sites in the West Thumb area; but significant quantities of Absaroka cherts and Jackson-area obsidians also are present at West Thumb sites, suggesting multiple points of origin for Native Americans who camped there in the past.
These generalizations of lake use apply only to the recent past. As we go farther back in time, linking sites to tribes becomes very difficult, if not impossible, largely because of the similar types of material culture of Native American peoples across the region.
The Subsistence Systems of Native Americans at Yellowstone Lake
Another major question for park archeologists is: How can we better understand the hunting, fishing, and gathering systems and the seasonality of Yellowstone Lake use by prehistoric Native Americans? In the 1980s, NPS archeologists were the first to speculate as to the function of the lake in the prehistoric settlement and subsistence systems in the pre-contact period. Mainly trying to figure out which seasons Native Americans used the lake area, those archeologists proposed that the lake was used during the winter to hunt animals at volcanic hot spots or, alternatively, during the spring to fish for cutthroat trout as they ran up the lake’s tributaries to spawn. However, their limited data resulted in inconclusive results, finding no faunal remains to indicate winter hunting or fish remains to indicate spring fishing. Regardless, the archeologists indicated that locations of hunting sites near thermal features and near stream confluences confirmed their interpretations. In addition, they cited the presence of “notched flakes” as indication that Native Americans produced wooden sticks to be used for fishing. No detailed descriptions or illustrations of the notched flakes were provided; as well, no blood residue analyses were performed to confirm or refute the wood-working and fishing hypotheses. Numerous stone tools have been examined for protein residues, with not a single one at Yellowstone Lake yielding evidence for wood or fish.
Nabakov and Loendorf’s (2002, 2004) work suggested that the various Native American tribes that used the lake incorporated a wide variety of subsistence strategies in their survival repertoire. While various tribes hunted and gathered many mammals and plants, fishing appears to have been uncommon for tribes at the lake, despite the abundance of fish. Among the tribes, the Shoshone and Bannock were perhaps the only tribes likely to have used the lake for fishing, if at all. Nabakov and Loendorf reported that “[the Northern Shoshone] fished in Yellowstone Lake . . . ”, although details and specific ethnographic accounts of fishing at the lake were not provided. Great Basin cultural anthropologist Julian Steward’s 1941 ethnographic report indicated that the Shoshone and Bannock fished extensively in the spring, mostly using brush dams and weirs (Steward 1941). Shoshone and Bannock legends describe how coyote spilled mother earth’s basket of fish (interpreted as Yellowstone Lake), forming the various inland northwest river systems, thus establishing that the Shoshone were well aware of fish in Yellowstone Lake (Nabakov and Loendorf 2002).
Therefore, since the Shoshone fished and were aware the lake contains fish, it is reasonable to assume that the Shoshone likely fished at Yellowstone Lake. This activity probably occurred in spring, sometime between May through July, depending on the timing of the lake thaw and spring fish runs. Nabakov and Loendorf’s informants, including Dick Washakie (son of the Shoshone Chief Washakie), as well as early ethnographer Ake Hultkrantz, confirmed that both the Northern and Lemhi Shoshone fished a lot and that there were no magical restrictions or other social limitations on who could fish, as there were with hunting activities. Nabakov and Loendorf, however, did not provide specific ethnographic accounts of the Shoshone fishing at Yellowstone Lake, only saying that the Shoshone were known to have fished. The ethnographic data indicated it is unlikely that the Blackfeet and Crow fished at the lake, both of whom focused on hunted and gathered resources, such as bison and camas, respectively, in their diets (Nabakov and Loendorf 2002).
If there is some question as to the extent of Native American fishing at Yellowstone Lake, ecological data fully support the viability of hunting and gathering at the lake in recent history. Ethnographic accounts of recent use of the Yellowstone region include the collection of a wide variety of plants, including roots, seeds, and nuts. Mammal hunting was also vital to lake area subsistence. Bears are still active at the lake, although Nabakov and Loendorf (2002) did not provide data to address Native American bear hunting in the Yellowstone uplands. Bear hunting is common to a host of northern-latitude hunter-gatherer groups across the globe; therefore, it is certainly reasonable to speculate that Native Americans in prehistory were attracted to Yellowstone Lake and its surrounding environs to hunt bear. The lake does not thaw completely until late May or early June, so bear hunters likely were at the lake at a time when ice was still thick enough to walk on to reach the islands (all of which have prehistoric archeological sites) between January and early May.
In support of this supposition, YNP’s bear management officer Kerry Gunther told me that he has observed bears on three islands and recorded a bear hibernation den on one of them. The hunting of hibernating bears on the islands certainly would have encouraged native hunters to walk across early spring ice, especially if the hunter had pre-scouted the presence of a den. This supposition could explain the presence of archeological sites on the lake’s islands and would not require construction of boats to make the trip.
Archeological Evidence for Hunting, Gathering, and Fishing at Yellowstone Lake
In the 1990s and 2010s, Paul Sanders from the University of Wyoming explored the seasonal use of the park by Native Americans within the nearby Hayden Valley, just north of the lake along the Upper Yellowstone River Valley. Following the work of YNP archeologist Ann Johnson at the Osprey Beach site at Yellowstone Lake, Sanders suggested only warm-season use by Native Americans of the higher elevation portions of the Yellowstone Plateau, including Yellowstone Lake, with movement downslope into lower elevation river valleys in winter. Sanders (2013) also doubted the earlier speculation for fishing, suggesting that “although preservation of fish bones is a problem, fishing-related artifacts (e.g., net weights or sinkers) have not been clearly identified at any site in the lake area or Upper Yellowstone River.”
More recently, archeologists Ann Johnson and Brian Reeves have speculated that the lake was exclusively used during warm months because of the lack of available resources at the lake in winter. However, they failed to provide information to support their ideas, admitting in their site report on the Osprey Beach site (Johnson and Reeves 2004) that “We have not found any seasonal indicators for sites around the lake.”
Because of the intense winters and deep snow, most interpretations of YNP seasonality posit a late spring to early summer start of the tribal-use cycle. However, I think individuals traveled to the lake earlier in the seasonal cycle, possibly in March or April, trips perhaps oriented around finding possible bear dens on the islands of Yellowstone Lake or in the hills above the lake. At the same time, these travelers surely scouted snow conditions to estimate the timing of plant availability and even perhaps the timing of cutthroat trout runs.
Excavation of numerous archeological sites at the lake also provides excellent data by which to interpret how Yellowstone Lake was used in the past. Analysis of animal and plant remains, as well as protein-residue analysis of stone tools, provides insight into the nature of hunting, gathering, and fishing at Yellowstone Lake. Subsistence information has been recovered at twenty-two sites at Yellowstone Lake, including sites in all areas of the lake and dating to a variety of time periods.
Based on animal bones and protein residue on stone tools excavated at archeological sites, elk, bison, deer, bear, sheep, beaver, rabbit, cat, and squirrel were hunted by Native Americans at the lake in the past. Animal, or faunal, remains are rare at Yellowstone Lake sites because the highly acidic soils deteriorate bone quickly. In fact, only four archeological sites have yielded identifiable bone fragments at lake area archeological sites. One, located on the northeastern lakeshore, the Late Prehistoric Windy Bison site yielded the remains of bison, elk, and sheep during excavations by Kenneth Cannon (MacDonald and Hale 2013) in the early 1990s. Two, unidentifiable bone fragments (possibly bison) were found at the Donner site in a Middle Archaic occupation on the southeast arm of the lake. Three, in 2016, my crew recovered a large bison leg bone dated to about 800 years ago, in association with obsidian flakes eroding from the edge of Dot Island in the middle of Yellowstone Lake (figure 5). Finally, in 2014, my crew recovered an elk toe bone from near a Late Archaic hearth dated to 2,000 years ago, located on the Flat Mountain Arm of the lake, a few miles east of the West Thumb (MacDonald and Hale 2013).
In addition to animal remains, 13 lake area sites yielded lithic artifacts with positive blood protein residue. Deer protein was identified on tools at six lake area sites, with bear identified at five sites. Rabbit was identified at four sites, with three each of bovine (bison), cat (bobcat, lynx, or cougar), and bighorn sheep. Dog (coyote, fox, or wolf) was identified at two sites, with rat (squirrel) and guinea pig (probably skunk or beaver) identified at single sites each. These protein identifications suggest a diverse hunting strategy at the lake, with the lithics dating from the Paleo-Indian to Late Prehistoric periods (9,500-300 years ago). The presence of bear protein on lithics from five lake area sites supports the hypothesis of active bear hunting at Yellowstone Lake in prehistory. That evidence also supports the idea of early spring trips to the lake by Native American hunters looking for bears waking up from hibernation.
Ethnobotanical plant remains and plant pollen have been identified at seven Yellowstone Lake sites, all excavated by my team between 2009 and 2016. These plant species include buckwheat, goosefoot, sagebrush, Jacob’s ladder, sedge, grass, sunflower, lily, and bitterroot. These species have edible and/or medicinal qualities and support the warm-season model of lake use because of their ripeness between May and September. Features in which these plants were found date variably to the Early Archaic, Middle Archaic, Late Archaic, and Late Prehistoric. This suggests long and consistent use of plants by lake area hunter-gatherers, at a minimum, during the most recent 8,000 years of prehistory.
Most significant in the subsistence data is the lack of any positive identification of fish remains or proteins on any of the tested materials at the dozens of sites studied at the lake. While UM’s protein residue analysis includes problematic lab results, many other studies, including ours analyzed at other labs, have also failed to identify fish protein on stone tools and fire cracked rock. Presumably, this means Native Americans did not fish at the lake very much, perhaps because of the abundance and ubiquitous availability of many other types of animals and plants for food.
Did Native Americans Use Boats at Yellowstone Lake?
Another fishing-related research question that needs answering is: Were canoes or other types of boats used by Native Americans at Yellowstone Lake? In their 2004 report on Osprey Beach, Johnson and Reeves (2004) explained how the lake’s islands contained archeological sites, pushing forward the notion that Native Americans used canoes to access the islands. Johnson et al. (2004) stated that “although direct evidence is lacking, we suggest seasonally resident Cody bands at Yellowstone Lake . . . probably fished, fowled, and perhaps used skin-covered boats on Yellowstone Lake.” Their speculation of boat use is further confirmed in illustrations produced for the Late Paleo-Indian Osprey Beach site by Johnson for public presentations on that important site (Johnson and Reeves 2013). But, she largely disregarded access to the islands when the lake was frozen because she believed that the frigid winter conditions were too harsh for Native Americans (Johnson et al. 2004).
Boats certainly would have facilitated travel around the lake’s shores and to the lake’s islands, as well as facilitated the transport of lithic raw material and other goods to the various lake areas. However, ethnographic and ethnohistoric literature is lacking any accounts of Native American boat use at Yellowstone Lake. Philetus Walter Norris’s 1880 superintendent report indicated the casual observation of a dugout canoe downriver on the Yellowstone River (well downstream of the lake) and another on Beaverdam Creek near the southeast corner of the lake. However, those canoes may have been used by historic period trappers and do not necessarily support the hypothesis of Native American boat use at the lake. Nevertheless, among the tribes who used the lake, the Shoshone were known to have used skin boats (but not canoes) in their collection of riparian resources in lower elevation lakes of the Great Basin (south of Yellowstone), as recorded by the anthropologist Julian Steward (1941). There are no ethnographic accounts available that suggest any of the tribes using Yellowstone Lake had canoes.
If boats, especially canoes, were built and used at Yellowstone Lake, we should expect to see evidence of their manufacture in the archeological record. But in all of the excavations by the UM teams around the shores of the lake, only one possible wood-working tool was recovered. This tool showed a heavy worked edge, likely on hard materials such as wood. On the southwestern shore of the lake, Ann Johnson and her colleagues noted the presence of two adzes at the Osprey Beach site, although it is unclear whether wear indicated woodworking for those tools. I am unaware of any other lake area sites yielding adzes or heavy-duty wood-working tools. If boats were utilized, it does not appear that they were of the dugout canoe variety; but possibly they could have been of the skin-boat (umiak) variety, known to have been used by the Shoshone in the Great Basin. Since the Shoshone frequented Yellowstone Lake, it is conceivable that they used skin boats there as well. However, no boats or boat parts have ever been identified to-date at any lake area site. Certainly, such finds would be remarkable at the lake, given the acidic nature of soils due to volcanism.
Stone artifact data can also be used to evaluate boat use. Presumably if boats were used to transport people around the lakeshore, it is reasonable that they also would have transported stone by boat to save energy and maximize stone material availability in tool manufacture. So, my prediction is that amounts of rock at sites should be more-or-less similar around the different areas of the lake shore if boats were used for travel, assuming Native Americans would have carried lots of stone with them. In contrast, if foot travel was emphasized, I predict that we should see significant reductions in the amount of stone in different areas of the lake. Under the walking option, Native Americans also would have reduced their stone tool kits to minimum levels to save energy as they walked around the lake.
Stone tool data do not seem to support a hypothesis that boats were used by Native Americans at the lake. The best example of this is to compare stone tools at sites on two areas of the lake that aren’t far apart: the northwest shore (near Fishing Bridge) and southwest shore (along the West Thumb). These areas are about 10 miles (15 km) apart by boat or about 30 miles (45 km) by foot along the undulating shoreline. If boats were used anywhere, this would presumably be the place, as it would have saved a great deal of time and effort. Therefore, we should see similar amounts of stone artifacts in the two areas, with the distance fall-off curve flat. In contrast, if humans walked between the two areas, we would expect there to be a significant fall-off in the amount of stone at sites in the two areas. The major presumption here is that the north shore sites were closest to the main source of material in the area, Obsidian Cliff. Presuming Native Americans traveling from Obsidian Cliff to the lake stopped first at Yellowstone Lake’s north shore, we should expect to see fairly large amounts of Obsidian Cliff obsidian at sites on the north shore. And if canoes were used, we should see similar quantities of stone at sites on the southwestern shore. But if people walked between the two areas, we should expect to see a large drop off in the amount of stone between Fishing Bridge and the West Thumb. Logically, people would have carried less stone with them if they walked than if they took a boat.
From 2009 to 2012 on the northwest lakeshore, the UM team excavated 70, 1-meter-square excavation units at 7 sites, yielding 13,995 stone tools and flakes for a mean of 200 artifacts per excavation unit (MacDonald et al. 2012). On the southwest shore along the West Thumb and vicinity, archeologists excavated 94 1-meter-square excavation units at 8 sites, revealing only 2,178 tools and flakes, a mean of 23 artifacts per excavation unit. Both of these areas yielded Obsidian Cliff obsidian and/or cherts from northern lithic sources. Therefore, while people moved regularly between the northwest and southwest shores, the conservation of material (as shown in the reduced numbers of artifacts) supports the hypothesis that they traveled on foot, rather than by boat, to get from Fishing Bridge to the West Thumb.
The overall character of all sites along the north shore of Yellowstone Lake is of lithic (or flaked stone) abundance; whereas on the southwest shore, it is one of lithic scarcity. The amount of stone recovered during excavations at sites on the south shore is about forty-two lithics per excavation square (5,557 lithics; 131 1-meter-square test units; 11 sites) compared to 164 lithics per excavation square at sites on the north shore (18,809 lithics; 115 1-meter-square test units; 13 sites). The sheer volume of lithics from test units on the north shore—18,809 lithics—compared to the south shore—5,557 lithics—is even more striking, considering that 16 additional excavation squares were conducted on the south shore compared to the north.
These stone artifact data suggest a significant fall-off in lithic use in locations farther from their geological sources, suggesting Native Americans walked around the lakeshore and did not actively travel along the lake shore using boats. I propose that this pattern of stone tool use supports my supposition that boats were not used by hunter-gatherers at the lake. If they were, such significant fall-offs in the amounts and weights of lithic material use would not be evident, since Native Americans would presumably have filled their boats with stone material as they canoed around the lake. Also, it is clear from the stone material source data discussed earlier, different groups from different regions likely camped on the different shores of the lake as well, supporting the idea that the lake was accessed on foot, not by boat.
Based on our UM archeological research at Yellowstone Lake between 2009 and 2017, we conclude that many different tribes of Native Americans actively used Yellowstone Lake in their daily lives over the last 11,000 years. In recent years, prior to the formation of the park, the Shoshone, Crow, Blackfeet, Nez Perce, among others, were likely the most active at Yellowstone Lake. Subsistence was focused on the collecting of dozens of distinct edible plants and the hunting of a variety of animals, including elk, bison, rabbits, deer, and bear. Fishing does not appear to have been an active part of the Native American diet, at least according to the rich archeological record at Yellowstone Lake. The reasons for the lack of fishing remain uncertain. As I discuss further in Before Yellowstone (MacDonald 2018), it is possible that native Yellowstone cutthroat trout did not arrive to Yellowstone Lake until the last few thousands years, well after Native Americans started to actively use the lake (since 11,000 years ago); thus, perhaps by the time Native Americans witnessed fish at the lake, they already had a well-established subsistence round that focused on the collection of plants and the hunting of animals.
Future research at Yellowstone Lake should determine when Yellowstone cutthroat trout arrived and further evaluate their role in the diet of Native Americans over the last 11,000 years. Current archeological research provides outstanding support for the fact that many tribes of Native Americans visited Yellowstone Lake since the retreat of glaciers in the Late Pleistocene. This history is rich in the remains of their daily lives, as evidenced by the thousands of artifacts at more than 300 archeological sites around every shore of the lake.