The site of the original Ft. Mandan, named in honor of the neighboring tribe and hosts of Lewis and Clark, is in some dispute, except for the fact that it currently is under the waters of the Missouri River. The Missouri has changed course many times over the years since Ft. Mandan was built, but no changes were as dramatic as when the Garrison Dam was constructed in the 1950's. Part of the Pick-Sloan Plan, Garrison submerged many sites behind it and further altered the downstream path of the already wandering river. Another Pick-Sloan dam, Oahe in South Dakota, also submerged a number of historic sites along the river. A reconstruction of Ft. Mandan currently exists approximately two miles south of the Lewis and Clark Interpretive Center in Washburn, North Dakota.
612 East Boulevard Ave.
Bismarck, North Dakota 58505
State Museum and Store: 8am - 5pm M-F; Sat. & Sun. 10am - 5pm.
We are closed New Year's Day, Easter, Thanksgiving Day, and Christmas Day.
State Archives: 8am - 4:30pm., M-F, except state holidays, and 2nd Sat. of each month, 10am - 4:30 pm.
State Historical Society offices: 8am - 5pm M-F, except state holidays.
phone: (701) 328-2666
fax: (701) 328-3710