They've got 465.6125 listed as a mobile 5 watt simplex frequency under their license. Perhaps that's what they are using for operations. You'll have to be fairly close to hear it if that's the case. The other 2 frequencies on that license are 453.875, which is listed here in the database as 'Fire Dispatch' and 458.875 which I'm sure is the input. ULS License - Public Safety Pool, Conventional License - KNHL669 - ROCKINGHAM, CITY OF if you want to take a look.
Rockingham Fire has switched to DMR. The initial page for station alerting is in analog, and I believe simulcasted on the County Fire Ops 1, but the rest of the unit traffic happens on the same frequency in DMR.