The Osage Nation Historic Preservation Office (ONHPO) proudly announces the full reacquisition of Sugarloaf Mound, the oldest known human-made structure in St. Louis and the last remaining Native American mound in a city once known as “Mound City.” Originally constructed between 600 and 1200 AD, Sugarloaf Mound is a sacred site connected to the Osage people’s ancestral presence in Missouri.
The reacquisition marks the culmination of a 17-year effort that began in 2008 when the Osage Nation purchased roughly one-third of the mound. As of 2025, the site is once again fully under Osage control. A vital partner in this achievement was CounterPublic, a St. Louis-based arts and culture organization that supported the effort through both advocacy and financial contributions.
“The Osage Nation Historic Preservation Office has been dedicated to securing Sugarloaf Mound for the Nation, and we consider this work an honor,” said Dr. Andrea Hunter, Osage Nation Historic Preservation Officer. “It has been a long 17-year journey, and I am thrilled to finally see the entire mound come under Osage Nation control. We are extremely grateful for the support of CounterPublic in making this happen; they have been and continue to be an excellent partner in this preservation effort.”
The Osage Nation maintains deep historical and cultural ties to the St. Louis region. Oral histories from the Dhegiha-Siouan people, supported by linguistic and archaeological evidence, confirm Osage ancestral presence in the area for over a millennium. Experts believe Sugarloaf Mound was likely either a Woodland period burial mound or a Mississippian period platform mound. It was constructed during a time when St. Louis was a major civic-ceremonial center linked to Cahokia and the East St. Louis Mound Group.
During the city’s expansion, nearly all of St. Louis’s original mounds were destroyed or repurposed for development—including homes, beer gardens, and other structures. By 1875, most had been leveled. Sugarloaf Mound, however, survived. It was added to the National Register of Historic Places on February 17, 1984. A house built on top of the mound in 1928 was purchased by the Osage Nation in 2009 and demolished in 2017. In 2025, the Nation—again in partnership with CounterPublic—successfully negotiated the transfer of the two remaining parcels that comprise the mound.
Preservation efforts are now entering a new phase. The Osage Nation is seeking funding for both immediate and long-term work, including the removal of remaining structures, stabilization of the mound, and the development of an interpretive center.
“We have a significant amount of work ahead of us to remove all the structures from the properties and stabilize the mound,” said Dr. Hunter. “Now more than ever, our office is dedicated to preserving this sacred site while also educating people about our rich history in the St. Louis area.”