Did you search fcc info on this site???
I am not sure what counties are by you but I found that freq is part of the New York State Wireless crap..
Search Results for 857.7375 in New York
Freq Out Freq In Tone Callsign Description Category County/Agency State
857.73750 0.00000 Trunked N/A New York State Wireless Network (800 MHz) Trunked System Statewide NY
857.73750 0.00000 Trunked N/A Redwood NY Statewide Wireless Network (SWN) Trunked System Suffolk NY
http://www.radioreference.com/modules.php?name=RR&freq=857.7375&action=isf&stid=36