Ok, let me chime in with my two cents of disinformation.
VSP Middlesex dispatches Waterbury and Berlin on 460.425. Listen for the "M" before the unit numbers. The four digit units prefixed with an "M" are Berlin (M11XX, as I recall), the three digit units prefixed with an "M" are Waterbury. Three digit units without an "M" are VSP.
460.175 is South Burlington. Some of you may hear an annoying buzz on that frequency. I believe Grafton Co. NH sheriff or some other entity in NH is using that freq. for their MDTs so that freq is not widely used by PDs east of the spine of the Green Mountains. Also be aware that South Burlington does use P-25 digital on that frequency too. I have never heard Waterbury PD on that frequency but I could be wrong about that.
Randolph (not in Washington Co.) is dispatched by VSP Royalton on 460.025, (PL 156.7). Yes, VSP Royalton shares that freq. with VSP St. Albans. Listen for M31X units on that frequency; those are Randolph units. Randolph also simulcasts VSP Royalton on 453.9125 but I have never heard mobiles on 458.9125. Orange Co. sheriff uses 460.200 and I have never heard a Randolph unit on that frequency but, again, I could be wrong about that.
Northfield PD does run their own frequency, 460.6375, as documented above.
Barre City PD runs on 460.075. Barre Town PD uses 453.450. Montpelier uses 460.050, as does St. Albans PD and both run a PL of 118.8. Montpelier PD dispatch is "800", St. Albans dispatch is "central".
Washington Co. sheriff uses 460.350 primarily and 460.450 rarely.
Hope that's some help. Happy listening!