PIERRE, (KCCR) — Starting Monday, some highways in Dewey County will go under the knife for milling and overlay work. The South Dakota Department of Transportation says a 20-mile section of U-S Highway 212 from a mile west of Dupree to the east side of Eagle Butte will be milled an overlaid with new asphalt. On top of the 212 project, South Dakota Highway 63 will have the same type of work completed from Highway 212 to 17 miles north of that intersection. Both projects will have one inch of surface cold-milled off with two inches of asphalt concrete replacing it. Traffic will be reduced to a single lane through work zones with flaggers and pilot cars in use to safely guide vehicles. Short delays can be expected through the work zones during daylight construction hours. The projects are expected to be completed in September of this year. The estimated cost of the project is 16-point-three million dollars.