Keystone Wye is an interchange of U.S. Route 16 (US 16) and US 16A located in the Black Hills of South Dakota, featuring two unique structural glued laminated timber bridges. The Keystone Wye is a three-level Directional T interchange for the two divided highways, constructed in 1967-1968 as part of a project by the South Dakota Department of Transportation (SDDOT) to convert US 16 to a four-lane highway between Rapid City and Keystone. It was designed by Clyde Jundt and Kenneth C. Wilson.