Harford County Hwy Maintenance Shop 1348 Cooptown Rd Forest Hill, MD 21050 Phone : (410) 692-7878 Business Category Government Offices-County Legislative Bodies Harford County--public Works, Highways Maintenance Shops, Jarrettsville Jarrettsville, MD 21084 Phone : (410) 692-7878 Business Category Government Offices-County Government Offices & Public Schools Harford County--public Works, Division Of Engineering & Construction, Bureau Of Highways, Highways Maintenance, Jarrettsville Jarrettsville, MD 21084 Phone : (410) 692-7878 Business Category Government Offices-County Government Offices & Public Schools