The breadth of river systems

I absolutely love what this guy has done with his representation of various American river systems, drawn in subway map style.

Even more impressive are the things I learned from studying these maps, including that a river passing through Great Falls Montana (a mere 512 km away from us) ends up in the Mississippi River; and that the Columbia river is fed by waterways as far north and east as Canal Flats in British Columbia (only 325 km away from us) and as far east as Wyoming.