Unfortunately, the given coordinates (latitude: 39.36390305, longitude: -77.74066925) do not correspond to a boat ramp named Chesapeake and Ohio Canal Trail Antietam in Virginia. These coordinates actually point to a location near Shepherdstown, West Virginia.

Therefore, it is not possible to provide accurate information about this specific boat ramp. However, in general, details about a boat ramp can typically be found through online resources such as state or local government websites, boating forums, or boating-related apps. It is recommended to use reliable sources and verify information with multiple sources to ensure accuracy.