Seim, South Dakota, was founded in 1894 and named after one of the first pioneer settlers in the area. In its prime in the early 1900s, the town had banks, newspapers, saloons, a post office, general store, hotel, livery, blacksmith shop, restaurant, barber shop, creamery, and school, while wagons were the most common form of transportation throughout the area. Seim was not located on the Bismarck-Deadwood Trail, which lay south of the Shadehill area, although the wagon trail leading out of Seim can still be found south of the reservoir. By 1918, most residents had moved away because the railroad was routed to the north and the highway was built to the east, leaving Seim nearly a ghost town by the time Shadehill Dam was constructed and the town slipped below the water.