Shadehill Reservoir is a reservoir on the Grand River in Perkins County, South Dakota, USA. The lake was created by the construction of Shadehill Dam by the United States Bureau of Reclamation in 1951. The reservoir has two primary inflows: North Fork Grand River and South Fork Grand River. The single Grand River serves as the only outflow. Species of fish in the lake include walleye, smallmouth bass, channel catfish, yellow perch, northern pike, and common carp.