Stretching from the point where the Susquehanna River flows into Chesapeake Bay, along the Pennsylvania border to West Virginia, North Maryland is a diverse region with everything from maritime to mountain activities. Frederick, home to several historic sites and museums, is an excellent place to explore Civil War history. Some of the region's attractions include a 40-mi (64 km) stretch of the Appalachian Trail, the National Museum of Civil War Medicine in Frederick, the Havre de Grace Decoy Museum in Harford County and the Hager House in Hagerstown. State parks and recreation areas are particularly abundant and well-stocked with facilities and amenities, but the area is most famous for its expansive hiking trails, which also yield exceptional cross-country skiing with the arrival of snow in the winter. Savage River State Forest is the largest member of Maryland's state forest system, attracting visitors eager to avail themselves of the biking and hiking trails, fishing waters and campsites.