Swains Lock: Photos and Maps

Chesapeake and Ohio Canal superimposed on lock 20 at Great Falls, filling

map of C&O Canal superimposed on lock 20 at Great Falls

Great Falls of Potomac from Olmsted Island observation deck (Maryland side) with river flow at 37,000 cfs

Great Falls from Olmsted Island observation deck on Maryland side of park, with river flow c. 37,000 cubic feet per second

Potomac River and C&O Canal near Swains Lock superimposed on Great Falls (seen from Virginia side) at 128,000 cfs

detail map of Potomac River and C&O Canal superimposed on view of Great Falls from Virginia side of park, with river flow c. 128,000 cubic feet per second

Lock 20 at Great Falls, filling complete

lock 20 at Great Falls, prior to opening upstream gates