55 Lodges, 486 Bodies, South Dakota's Grim Relic

Near modern-day South Dakota, on the banks of the upper Missouri River, a dreadful occurrence unfolded. Known now as the Crow Creek Site, a U.S National Historic Landmark, this was the location of a bloody inter-tribal skirmish. At least 486 individuals met their end within a fortification ditch. The records, however, don't detail the identities of these people or their subsequent journey.

In excavations of 1978 and beyond, the remains of two ancient groups were discovered: the Siouan-speaking Middle Missourians and the Caddoan-speaking Central Plains people. The records don't disclose whether these groups coexisted in peace.

Today, the site is under the custody of the US Army Corps of Engineers, and the descendants of the Middle Missouri and Central Plains people reside in North Dakota as part of the Mandan and Arikara nations, respectively.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons