U.S. Highway 12 - S.D. Highway 1806 and S.D. Highway 63
Project Summary:
U.S. Highway 12 – From 12 miles east of McLaughlin to west of Mobridge
Full-depth reclamation completed in 2025 and asphalt concrete surfacing on U.S. Highway 12 will address cracking and rough joints. Subgrade reconstruction on S.D. Highway 1806 will correct heaving and restore a normal crown. Additional milling and resurfacing on Highway 1806, S.D. Highway 1806P and S.D. Highway 63 will improve ride quality. Guardrail will be replaced at bridges, and culverts repaired as needed.
Project Updates:
May 4, 2026:
On Monday, May 4, 2026, paving operations are beginning for the multi-year project on U.S. Highway 12 from Mobridge to the west approximately 14 miles. Work will also take place on S.D. Highway 1806 both north and south of Highway 12. The project includes placement of a two-inch lift of asphalt concrete.
Traffic will be reduced to one lane with flaggers and a pilot car guiding traffic during working hours. Motorists should expect delays of up to 15 minutes and are encouraged to reduce speed and use caution when traveling through the work zone. During non-working hours, traffic will return to normal operations.
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April 17, 2026 - Anticipated Work:
Spring work started the week of April 13 with culvert replacement east of the Oak Creek Bridge and base-course reinforcement north of the Wakpala School on S.D. 1806. Work on the slide repair on Highway 1806 south of U.S. Highway 12 has also started and should be nearly complete by the end of April. Culvert repair work will continue on Highway 1806 north of Highway 12.
Anticipated Work in May 2026:
Culvert replacement and subgrade repairs on Highway 1806 north of Highway 12 should be completed in May. Slide repair on Highway 1806 south of Highway 12 should also be completed in May.
The second lift of asphalt concrete will be placed on Highway 12 west of Mobridge. Milling and asphalt-concrete resurfacing will also take place in May on the following routes: Highway 1806 south of Highway 12, Highway 1806 north of Highway 12, the Highway 1806 Spur into Wakpala, and S.D. Highway 63 north of McLaughlin.
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On Monday, April 13, 2026, a project is scheduled to begin on U.S. Highway 12 from Mobridge west approximately 15 miles and on S.D. Highway 1806 both north and south of Highway 12. The Highway 12 project will primarily involve pipe and guardrail corner improvements on the shoulders of the highway.
On Highway 1806 north of Highway 12, work will include mainline pipe installations and short grading sections. Traffic will be reduced to one-half width in these work zones during daytime hours, with flaggers and a pilot car guiding the traveling public.
On Highway 1806 south of Highway 12, work will focus on a slide repair. Traffic will be controlled with stop signs through the work zone. At times during the daytime, flaggers and a pilot car will guide the traveling public.
Commuters should be alert through the entire work zone for workers adjacent to moving traffic, construction vehicles entering and exiting the work zones, and changing traffic patterns.
Nov. 21, 2025:
Oct. 15, 2025 – Nov. 15, 2025:
Completed Work: On U.S. Highway 12, the contractor completed final shaping and priming. Paving of the first lift of asphalt concrete was finished on Oct. 30. Permanent pavement markings were placed and completed on Nov. 5.
Anticipated Work Nov. 15, 2025 – Dec. 15, 2025: No additional work is planned for the remainder of the season. Work is expected to resume in spring 2026 and will include completion of pipe work and placement of the final lift of asphalt concrete on U.S. Highway 12; cold milling, asphalt concrete resurfacing, and pipe work on S.D. Highway 1806 (north of U.S. 12) and S.D. Highway 1806P (Wakpala Spur) and S.D. Highway 63 (north of McLaughlin); and cold milling and asphalt concrete resurfacing on S.D. Highway 1806 (south of U.S. 12).