Mandan, N.D. (AP) The Knife River Indian Villages National Historic Site is celebrating its 40th anniversary this weekend.
A ceremony is planned from 1 to 4 p.m. Central time on Sunday at the site near Stanton.
The site is where Hidatsa and Mandan Indian culture flourished around earth lodge villages for several centuries. Explorers Lewis and Clark visited the site in 1804 to 1805 when they wintered at Fort Mandan a few miles away.
Congress in 1974 approved making it a national historic site under the administration of the National Park Service. President Gerald Ford signed the bill.