History of On-a-Slant

Long before Lewis and Clark ventured up the Missouri River in 1804, the Mandan people had been thriving on a very productive agricultural lifestyle in the Heart River area. For most of a thousand years, the Mandan (Nu'eta) called the region home, living in a succession of earthlodge villages. Rich in culture and tradition, Mandan men hunted buffalo and other game, while women grew several varieties of corn, squash and beans.  Food surpluses and more-or-less permanent settlements led to trade with other Native American nations and the Mandan became central to an ancient inter-tribal trade network.  

Around 1575, families from three nearby villages came to build a fortified village on a tract of gentle sloping land located on the west bank of  the Missouri River, about a mile south of its confluence with the Heart River. This is the village known to history as On-a-Slant. 

In 1781, the Mandan of On-a-Slant village suffered greatly during a smallpox epidemic that swept from Mexico to Canada and from the Mississippi to the Pacific coast. The last chief of On-a-Slant, Good Boy, rallied the survivors and joining with survivors from other villages, moved north to establish a city near their Hidatsa allies, near what is now the Knife River Indian Villages National Historic Site.

The Mandan of On-a-Slant Village left a legacy that still lives on as interpretive guides take you through six reconstructed earthlodges, in an effort to tell the Mandan story.

Tours are available from Memorial Day to Labor Day- 9 a.m. to 7 p.m. and limited hours in other seasons.