Dan,

I certainly did not see (or hear) hundreds (something more in the tens), but 
Tundra Swans were flying last night just after dusk over our Bel Air home here 
in Harford.  They were headed NW, which could/would be in alignment with a 
Susquehanna Flats departure.

Rick Cheicante
Harford county
Bel Air, MD