By Jordan Butler, November 9, 2021
Antietam Iron Works Bridge Marker
| On Harpers Ferry Road at Limekiln Road, on the right when traveling east on Harpers Ferry Road. |
| On National Pike (U.S. 40) 0.2 miles west of Mapleville Road (Maryland Route 66), on the right when traveling south. |
| On Roxbury Road, on the right when traveling south. |
| On Old National Pike (Alternate U.S. 40), on the right when traveling north. |
| On Poffenberger Road, on the left when traveling west. |
| On Poffenberger Road, on the left when traveling west. |
| On West Baltimore Street / Oak Ridge Drive, on the right when traveling west. |
| On Garis Shop Road, on the right when traveling west. |
| On Summit Avenue, on the right when traveling north. |
| On North Potomac Street (Maryland Route 65) at West Washington Street (U.S. 40), on the left when traveling south on North Potomac Street. |
| On Coffman Farm Road, on the right when traveling west. |
| On Keedysville Road, on the right when traveling west. |
| On Keedysville Road, 0.5 miles west of Shepherdstown Pike (Maryland Route 34), on the right when traveling west. |
| On Keedysville Road, 0.5 miles west of Shepherdstown Pike (Maryland Route 34), on the right when traveling east. |
| On Keedysville Road, 0.1 miles west of Shepherdstown Pike (Maryland Route 34), on the left when traveling west. |
| On Valley Road, 0.2 miles west of Garretts Mill Road, on the right when traveling east. |
| On Lappans Road (Maryland Route 68), on the right when traveling west. Reported damaged. |
| On Leiters Mill Road, on the left when traveling north. |
| On Old Forge Road, on the right when traveling east. |
| On Rohrersville Road (State Highway 67) at Park Hall Road, on the right when traveling south on Rohrersville Road. |
| On North Hall Street, on the right when traveling south. |
| On Boonsboro Pike (State Highway 34), on the right when traveling east. |
| On Boonsboro Pike (State Highway 34), on the right when traveling east. Reported missing. |
| On East Chapline Street, on the right when traveling east. |
| On North Main Street, on the right when traveling north. |