Highway Department Shop 407 W 11th St Yankton, SD 57078 Phone : (605) 665-7751 Business Category Highway & street construction Grading Contractors Road Maintenance Yankton County Of--yankton, Hiway Dept Shop 407 W 11th St Yankton, SD 57078 Phone : (605) 665-7751 Business Category Government Offices-County Government Offices & Public Schools