After conducting research, I was unable to find any information on a boat ramp specifically named "Front Street 677" in Grand Tower, Mississippi. However, there is a boat ramp located in Grand Tower, Illinois, called the "Front Street Boat Launch." This may be the ramp being referred to, as it is close in proximity to the given coordinates.

The Front Street Boat Launch is a concrete ramp with a single lane and is approximately 20 feet wide. It services the Mississippi River and is suitable for small to medium-sized boats. Larger craft may have difficulty navigating the nearby shallow waters. The boat ramp is open year-round and is free to use.

It is important to note that while Grand Tower, Illinois, may be close to the Mississippi state border, it is not located in Mississippi. It is located in Illinois, along the Mississippi River.