There's a good chance that it was the "National EMS Memorial Bike Ride 2010". The ride started Saturday going from Portland ME to Nashua NH. Sunday, from Nashua to East Hartford CT. Monday, from East Hartford to Tarrytown NY. The last rest stop Monday was at the Bethel Fire Department before continuing on to Tarrytown. The final destination was Washington DC.
I say this because I was involved and that's about the time frame we went through that area.
More info here:
http://muddyangels.com/