Located where Catoctin Mountain (the easternmost ridge of the Blue Ridge mountains) meets the rolling hills of the Piedmont region, the Frederick area became a crossroads even before European explorers and traders arrived. Native American hunters possibly including the Susquehannocks, the Algonquian-speaking Shawnee, or the Seneca or Tuscarora or other members of the Iroquois Confederation) followed the Monocacy River from the Susquehanna River watershed in Pennsylvania to the Potomac River watershed and the lands of the more agrarian and maritime Algonquian peoples, particularly the Lenape of the Delaware valley or the Piscataway and Powhatan of the lower Potomac watershed and Chesapeake Bay. This became known as the Monocacy Trail or even the Great Indian Warpath, with some travelers continuing southward through the Great Appalachian Valley (Shenandoah Valley, etc.) to the western Piedmont in North Carolina, or traveling down other watersheds in Virginia toward the Chesapeake Bay, such as those of the Rappahannock, James and York Rivers.