Contact Info
Missouri River Institute
The University of
South Dakota
414 E. Clark Street
Science Center
Vermillion, SD 57069

Financial support for website development provided by the
Living River Group
of the
Sierra Club




Site Description:

Bon Homme Island was historically located about 12 miles upstream of Gavins Point Dam, and is now submerged beneath Lewis and Clark Lake. The Island gave its name to Bon Homme County in South Dakota, just north of the island, and to the former Bon Homme Colony. Lewis and Clark first arrived at Bon Homme Island September 1st, 1804, camping two nights on the island. Journal entries written by the crew detail the 'ancient fortifications', or old military forts, they discovered on the island. These 'ancient fortifications' were actually naturally occurring sand dunes.

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