Keywords: Lock 1 plan of Great Falls Patowmack Canal.png en Drawing of Lock 1 on Great Falls Skirting Canal HABS says HAER VA 30-GREFA 1A- sheet 1 of 1 - Potowmack Company Great Falls Canal Lock No 1 Great Falls Fairfax County VA LOC-image hhh va1445 Historic American Buildings Survey VA-13A 38 99806 -77 28861000000001 Patowmack Canal |