Keystone Wye

The Keystone Wye is a road interchange in the Black Hills that connects U.S. Route 16 and US 16A using two glued laminated timber arches spanning three levels. The structure uses wooden components to carry traffic across different elevations.

Engineers Clyde Jundt and Kenneth C. Wilson designed this infrastructure in 1967 using wooden arches as primary structural elements. It was built to support Norbeck's vision of a modern route through the Black Hills.

The interchange name comes from Senator Peter Norbeck's 1930s road system, which linked tourist destinations like Mount Rushmore and Black Elk Peak. This connection was part of a larger plan to open up the Black Hills to travelers.

When visiting, remember that this is a functional road interchange designed for through traffic. A 2021 renovation updated the wooden decks and asphalt surfaces, ensuring the structure remains safe and passable.

Three wooden arch pieces that failed quality inspections were repurposed into a pyramidal sculpture. The artwork was later relocated near the Sitting Bull Crystal Cavern Dance Pavilion.

Location: South Dakota

GPS coordinates: 43.92470,-103.44200

Latest update: December 11, 2025 18:07