The site was a meeting, trade and culture center for prehistoric native tribes from areas all around the present state of Washington. Prior to 1850, the site was used as a trade center and campground for the various bands of Native Americans that now make up the Yakama Indian Nation. The fort was built in the late 1850s by future Civil War general Robert S. Garnett and was in use for three years. In 1859, the military turned the fort over to the Yakama Indian Agency. The fort was then converted to an Indian school and the Yakama Indian Agency managed its affairs from the site until the early 1900s. The park was established in 1956.
Fort Simcoe State Park is located in an old oak grove watered by natural springs. It is a , day-use heritage park on the Yakama Indian Reservation. The park is primarily an interpretive effort, telling the story of mid-19th century army life and providing insights into the lifeways of local Native American culture. Five original buildings are still standing at the fort: the commander's house, three captain's houses and a blockhouse. Various other buildings have been recreated to appear original. Houses are filled with period furnishings. Due to its unique historic significance, the park was placed on the National Register of Historic Places in June, 1974.