Middle Creek (Toms Creek tributary)  Middle Creek is a  tributary of Toms Creek in Pennsylvania and Maryland in the United States. Middle Creek is born on the eastern slope of the Blue Ridge Mountains, and from there flows through Adams County, Pennsylvania and Frederick County, Maryland to join Toms Creek near Emmitsburg. Water from Middle Creek flows via Toms Creek, the Monocacy River, and the Potomac River to Chesapeake Bay and eventually the Atlantic Ocean.