Palace Site
The Palace Site is a ca. 7,000-year-old archeological site in Des Moines, Iowa with evidence for some of the oldest houses west of the Mississippi valley and the oldest human burial in Iowa. Since 2011, the site has yielded 6,000 or more artifacts, as well as the remains of two humans, a woman and an infant, that are the oldest human bones to be found in the state.  A spear point found beneath the woman's lower back appears to have been intentionally placed there during burial. Also found in the grave were a small polished stone, a flint chip from stone tool making, and wood charcoal. The OSA Burial Protection Program is legally responsible for investigating, preserving, and re-interring ancient human remains.

Details
The excavation took place from December 2010 to May 2011 south of Vandalia Rd., north of the Des Moines River and on the west edge of the existing wastewater treatment plant. A short documentary of the excavation is available on YouTube. The site is so well-preserved and complete that the 6,000 or more artifacts found provide researchers with exciting insight into the types of tools the people in the village used, the types of animals they kept and ate and the types of seeds they planted.  The site, nicknamed “the Palace” because of its size and preservation, yielded the remains of two humans, a woman and an infant, that are the oldest human bones to be found in the state.

State Archaeologist John Doershuk states that the site was preserved so well because of a quick river flood that sealed the deposits and preserved the items. The site was discovered during construction of a new wastewater treatment facility. Anytime federally permitted or funded construction is occurring, archaeologists are called to perform an evaluation of potential archaeological sites in the area.

In late March, as part of planned sampling near the southeast margin of the site, the crew unexpectedly discovered a grave 7 feet below the surface. Researchers haven't determined the family relationship of the deceased, but preliminary analysis—including a radiocarbon date calculation based on wood charcoal from the burial feature—indicates that the individuals died 6,680 to 6,890 years ago. The grave had been disturbed by erosion at some point after interment, long before modern construction activities began at the site. Systematic exploratory excavation of the surrounding area identified no additional burials. Red ochre, a powdered mineral used by ancient cultures worldwide, was abundant, covering the remains. A spear point found beneath the woman's lower back appears to have been intentionally placed there during burial. Also found in the grave were a small polished stone, a flint chip from stone tool making, and wood charcoal.

The OSA Burial Protection Program is legally responsible for investigating, preserving and reinterring ancient human remains. Since Iowa's burial protection law passed in 1976, the program has handled over 2,000 projects in 98 of Iowa's 99 counties. Removal and reburial of the human remains found at the Palace site is taking place in consultation with descendant American Indian peoples and members of the OSA Indian Advisory Council, and in accordance with state and federal laws. State Archaeologist John Doershuk said it's not possible to link the individuals to a specific American Indian tribe. Archaeologists do know that people living in that time period survived by hunting and gathering natural resources, rather than farming.

"The location, at the boundary of a large sand bar along the ancient Des Moines River, would have been appealing to people living the hunting-gathering lifeway," he said. "It would have been a lush area, and we've discovered a broad spectrum of animal remains near the house areas: deer, raccoon, turkey, shellfish, bison and lots of turtles. The river would have been a key route for transportation."

The age of the site was determined by radiocarbon dating based on wood charcoal from the burial feature and also the spear point found there, by matching it to the time frame of other similar artifacts found in the Midwest, Doershuk said. The crew also used laser technology to map more than 12,000 archaeological data points so they can develop 3-D models of the site with computer software.  While construction on the wastewater treatment plant at the site continues, there is adjacent, un-excavated land that researchers believe will yield more archaeological finds, and they are working on a preservation plan.

At the site, the UI-based Office of the State Archaeologist (OSA) found the remnants of four oval-shaped deposits, possibly houses, as large as 800 square feet and furnished with hearths. These structures were likely built of wooden poles sealed with clay. Two partial skeletons were unexpectedly found at the site late in the project. The remains of a woman and an infant are the oldest human remains found to-date in the state by about 1,500 years. According to Bill Whittaker, a co-director of the dig “It became clear very quickly that the site was something spectacular — something none of us had seen before or probably will ever again, as well-preserved house deposits of this age are extremely rare west of the Mississippi River Valley,” 

A significant unexcavated portion of the Palace is adjacent to the construction zone, and state and federal officials are working with the Water Reclamation Authority to develop a long-term preservation plan for the intact areas. While the exact boundaries of the Palace site are unknown, archaeologists said there is evidence of both older and more recent prehistoric occupations than the 7,000-year-old structures; laboratory analyses of data from these deposits are ongoing. Doershuk said while only two sets of human remains were located in the excavation, additional burials might exist within unexplored portions of the site. As additional details about the site emerge, the OSA will produce a formal report, a website gallery of images from the house areas, and educational publications and presentations to share with the public what they've learned.