Circuit Court 410 Walnut St Yankton, SD 57078 Phone : (605) 668-3095 Business Category State Courts County Government-Courts Courts South Dakota State Of--yankton, Circuit Court 5 & Walnut Yankton, SD 57078 Phone : (605) 668-3095 Business Category Government Offices-State Government Offices State & Local Government Offices & Public Schools South Dakota State Of--circuit Court 5 Walnut Yankton, SD 57078 Phone : (605) 668-3095 Business Category Government Offices-State Government Offices State & Local Government Offices & Public Schools