Fort Union Trading Post National Historic Site is located in North Dakota and Montana, near the confluence of the Missouri River and Fort Peck Lake. Established in 1828, it served as a vital trading hub for fur traders, Native Americans, and settlers. The fort facilitated trade between the American Fur Company and various Indigenous tribes, including the Assiniboine and Sioux. Today, the site preserves the history of the fur trade era and features reconstructed buildings, interpretive exhibits, and scenic views. Visitors can explore the fort's history through guided tours, educational programs, and special events that highlight its cultural significance.