Sleppy Holow EMS I believe is only dispatched by 60 Control while the Medics are duly dispatched by Mount Pleasant PD and 60 Control.
Sleppy Holow EMS dispatch is 155.775 DPL 441. Additionally, dispatch only can be heard on the new North 2 Paging frequency, 477.025 PL 156.7. Then after the dispatch on either of these frequencies, operations are moved to the Fire/EMS 12 TG on the
Westchester P25 Trunked system. Sleppy Holow EMS (SHVAC) has 3 BLS Ambulances, staffed by EMTs, not paramedics. 73B1, 73B2 and 73B3.
The Mount Pleasant Medics (37 Medics) as a whole are duly dispatched by Mount Pleasant PD and 60 Control, as they do serve other districts besides Sleppy Hollow. The medics can be heard on the Mount Pleasant EMS frequency 155.88 PL162.2 when dispatched by MPPD. Additionally, 60 Control dispatches them. Dispatch only can be heard on the new North 2 Paging frequency, 477.025 PL 156.7. Then if the medic need to communicate with 60 they will do so on the Fire/EMS 12 talkgroup on the
Westchester P25 Trunked system. Either or they are equipped with both radios so they can easily communicate to the proper dispatch agency. Mount Pleasant Medics provide ALS service and ride in flycars, there are 2 or 3. 37M1, 37M2 and 37M3
Typically when there is a EMS call in the village, an ambulance, and a medic will respond depending on the nature of the call. To monitor the whole covo I would suggest listening to 155.775 and Fire/EMS 12 on the trunked system.
So, I haven't actually heard any traffic from 463.2875 so I don't know what WEMS does with that channel. 155.535 is for the 45 Medics in Northern Westchester, and some other agencies.
Westchester EMS aka WEMS is an EMS agency providing emergency and non-emergency ambulance and paramedic fly-car services throughout Westchester County. You can read more about their services
here.