Business Loop I-90 - Spearfish

The Spearfish business loop for I-90 begins at Exit 10 opposite U.S. 85 north to Belle Fourche. The 5.2 mile route follows North Avenue through North Spearfish and Main Street along the old alignment of U.S. 14 and 85 to the Spearfish city center. Turning east along Colorado Boulevard, U.S. 14A accompanies the business loop as it reconnects with the freeway at Exit 14. The route is referenced from the I-90 mainline and somewhat signed across the city.

A $28 million project redesigned the diamond interchange at the east end into a single point urban interchange. The project ran through June 1, 2018 (SDDOT, 2018).