Just noticed that this freq IS in the RR db for Perry Co. as follows:
453.46250 KB92334 County Services Municipal Services Perry County Perry PA
... and as you heard, it's apparently used for fire simulcast. And maybe more... keep listening. In fact, keep searching... you may find others.
I also just noticed these listings for Perry fire in the RR db:
453.06250 KB92334 RM Perry FD Ops Countywide Fire - Repeater FM Fire-Tac
465.33750 KB87733 RM Perry FD FG Fireground Repeater FM Fire-Talk
What are you hearing on them? And there are several other UHF freqs listed as "Municipal Services". You may want to check them out. Link to the Perry page in RR db: http://www.radioreference.com/apps/db/?ctid=2290