Upward Sun River Site - Arctic Paleoindian Site in Alaska

Paleoindian and Pre-Clovis Upward Sun River Site

Map showing the location of the Upward Sun River Mouth site
Map showing the location of the Upward Sun River Mouth site. Image courtesy of Ben A. Potter, University of Alaska Fairbanks

The Upward Sun River Site (USR), called Xaasaa Na'in (haw-SAW NA) in Athabaskan, and the Little Delta Dune site, 49XBD-298 or the Upward Sun River Mouth site in the scientific literature, is a buried Paleoindian and Paleoarctic site located near the confluence of the Little Delta and Tanana rivers in central Alaska. Three 11,500 year old child burials discovered at Upper Sun River represent the earliest evidence for complex mortuary behaviors among Terminal Pleistocene Beringeans and North American Paleoindians yet discovered.

The Upward Sun River site is buried within a linear, loess-mantled sand dune, which has been geologically stable since the late Pleistocene. Four archaeological occupations have been identified within the 2.6 meter (8.5 foot)-thick loess mantle of the dune, dated between 11,420 and 8800 radiocarbon years before the present (RCYBP).

Site Stratigraphy 

  • Component 4, ca 80 cm below modern surface (b.s.), 8880 +/- RCYBP
  • Component 3, ca 100 cm b.s., 9970 RCYPB (11,600-11,270 cal BP), hearths, house and burials, associated with the Denali Complex
  • Component 2, ca 140 cm b.s., 9670 +/-40 RCYBP
  • Component 1, ca 240 cm b.s., 11,250-11,420 RCYBP, hearth

Components

The oldest occupation (Component 1), is a pre-clovis site represented by chert waste flakes and animal bone fragments associated with a hearth. Although not much is known about this occupation yet, it represents one of the earliest evidence for human migrations from Beringia identified in arctic North America.

Animals represented in the Component 1 assemblage include waterfowl, large mammals such as a bison, moose or elk, fox, and other small mammals. Scholars point to a fall occupation for Component 1, based on the presence of bearberry seeds and waterfowl.

Most intensive investigations to date at USR have been focused on Component 3, a substantial summer occupation with a semi-subterranean residence, hearths and three child burials beneath its floors.

Living at USR

The people living at Upward Sun River Site represented by Component 3 excavated their house some 27 cm (10.6 in) below the surface of the ground. The house plan was roughly circular and about 3 m (10 ft) in diameter; six postmolds were identified representing roof supports. Researchers believe the house was typical of a semi-subterranean pithouse, as seen at other houses in the region of the Bering Strait such as at Ushki Lake 6 in the Kamchatka peninsula of Siberia. Ushki Lake 6 also has human burials, including one child burial within the house floor, although it is not a cremation.

Animal bones identified in the hearth pit include salmonid fish and small mammals, including ground squirrels and waterfowl, primarily ptarmigan. This collection suggests a summer occupation for Component 3. Stone tools recovered from the site outside of the grave goods listed above include bi-pointed bifaces, also associated with Denali Complex or Paleoarctic Tradition.

DNA and stable isotope analysis of a sample from the 308 salmon bones retrieved from the cooking hearth and human burials in Component 3 was reported in 2015 (Halffman et al). DNA established the species as Oncorhynchus keta (chum salmon); and stable isotope analysis indicates the salmon were anadromous--they lived in the ocean but returned to freshwater rivers to spawn.

This represents the earliest use of salmon in North America, and additional evidence that Paleoindians were not simply big game hunters.

Component 3: Burials at USR

Excavations conducted during the summer of 2010 by the University of Alaska focused on Component 3, where a burial pit-hearth was identified within a semi-subterranean house feature. The burial pit-hearth is an oval depression, some 45 centimeters (17 inches) deep by 130 cm (51 in) wide at the top and 80 cm (31 in) wide at the base. Cremated remains of a human child were identified within the top of the deposit; and at its base were animal bones, suggesting that this pit was not created specifically to inter the child's remains, but was probably originally a cache or storage pit.

Twenty radiocarbon dates taken on charcoal from the pit and associated areas within and near the house returned an average of 9990+/- 30 RCYBP, which calibrates to about 11,280-11,620 calendar years ago (cal BP). The child was placed in the pit and burned; only approximately 20% of the skeleton is left. Researchers believe this child was between 2-4 years old at the time of the burial. The child's unerupted shovel-shaped incisors have a "Sinodont" pattern, supporting the interpretation that this child was related to northeastern Asian peoples and Native Americans. This Upward Sun River individual (called Xaasaa Cheege Ts’eniin (haw-SAW CHAG tse-NEEN) or Upward Sun River Child) represents one of the earliest (and youngest) human burials reported in the North American continent.

Infant Burials

Excavations below the residential feature were conducted in 2013, and they revealed two additional child burials, unburned infant skeletons interred within a circular pit directly below the cremation hearth where the first burial was found.

The lower burial pit had a flat bottom with steep sides and the fill was rich with red ochre. The presence of ochre within the burial represents ritual activities, an aspect of human burials noted at many paleoindian sites. The two infants and grave goods were placed in the bottom of this pit.

The skeletal remains were largely complete, and the position and arrangement of the infants suggests they were wrapped in shrouds before being interred.

One of the burials was an infant, who survived birth for between 5-20 weeks. The other was a late stage fetus: while DNA studies have yet to be completed, scholars are tentatively suggesting that they may have been twins.

Grave Goods and DNA Investigations

In 2015, a genomic study (Tackney et al) of two of the children from Component 3 revealed that they were descended from two different mitochondrial lineages, both of which are rare in modern northern Native American populations. At perhaps 2,000 years after the first colonization, the population at USR had a greater genomic diversity than modern groups. Tackneyand colleagues argue that is evidence supports the Beringia Standstill Hypothesis: that people from Siberia were stranded within the Beringia for several thousand years before gaining access to North America.

Grave goods placed in the pit included four rods made of elk antler, and two projectile points, all coated with red ochre. The rods are similar to but larger than is typical from Paleoindian samples such as the Anzick Clovis site in Montana, and similar in size to those recovered from the Yana Rhinoceros Horn Site in northern Siberia. The rods are beveled, with hafting marks and edge grinding, and are interpreted as parts of an atlatl hunting system.

The points are lanceolate bifacial points, consistent with Paleoarctic Denali complex "willow leaf" shaped points.

Sources

  • See the official Upward Sun River website from Ben A. Potter for additional photos and information about ongoing investigations.

This glossary entry is a part of the About.com guide to Paleoindians, and the Dictionary of Archaeology.

Halffman CM, Potter BA, McKinney HJ, Finney BP, Rodrigues AT, Yang DY, and Kemp BM. 2015. Early human use of anadromous salmon in North America at 11,500 y ago. Proceedings of the National Academy of Sciences 112(40):12344-12348.

Potter BA, Irish JD, Reuther JD, Gelvin-Reymiller C, and Holliday VT. 2011. A Terminal Pleistocene child cremation and residential structure from Eastern Beringia. Science 331:1058-1062.

Potter BA, Irish JD, Reuther JD, and McKinney HJ.

2014. New insights into Eastern Beringian mortuary behavior: A terminal Pleistocene double infant burial at Upward Sun River. Proceedings of the National Academy of Sciences Early Edition. doi: 10.1073/pnas.1413131111

Potter BA, Reuther JD, Bowers PM, and Gelvin-Reymiller C. 2008. Little Delta Dune Site: A Late-Pleistocene Multicomponent Site in Central Alaska. Current Research in the Pleistocene 25:132-135.

Tackney J, Potter BA, Raff JA, Powers M, Watkins MS, Warner D, Reuther JD, Irish JD, and O'Rourke DH. 2015. Two contemporaneous mitogenomes from terminal Pleistocene burials in eastern Beringia. Proceedings of the National Academy of Sciences Early Edition.