Fort Whoop-Up is a replica of the original whisky trading post that stood near the confluence of the Oldman and St. Mary rivers in the 1870s. The original fort was built by American traders from Montana who were selling illegal alcohol to First Nations people in what was then essentially ungoverned territory. The replica, located in Indian Battle Park inside the Oldman River valley, does a good job of conveying what the fort looked like and what happened there.
The interpretive centre inside the fort tells the full story of the whisky trade, the buffalo robe economy, and the arrival of the North-West Mounted Police who effectively put the fort out of business. It also covers the broader history of the region's Indigenous peoples — the Blackfoot Confederacy, the Cree, and the impact of the 1870s on both. The site sits in the same valley where the last major battle between First Nations peoples on Canadian soil took place, the Battle of the Belly River in 1870, and that history is addressed as well. The park around it is pleasant for walking.