Loudon County P25 - 172.4625 4F9 NAC - NPS?

[Gilligan]

I was at Dulles Airport today and found a new P25 freq while searching the fed band. Picked up 172.4625 w/ NF9 NAC, which is common to the National Park Service. Nothing listed in the database so I thought I'd post here and see if anyone local to the area can give a listen and see who it is... Thanks!

 

[loco-lee]

To a wildland firefighter, that looks like a NIFC Air-Ground channel. If you saw it with a NAC similar to Parks or Forestry - that might make a lot a sense. In use near an Airport - might make sense too. Good find!

 

[freqhopping]

Just tuned in tonight. Sounds like NPS. I had been getting only encryption, but I just heard units 624 and 625 talking about searching for an animal without any luck. Then a dispatcher came on running a vehicle reg for a unit not heard.

Update: Same comms as 171.7 4F9 - NPS Shenandoah Nat Park - Hogback Mountain

 

[CVASSB]

There is P25 activity on 172.650,172.675,and 172.925 Mhz,and others in this frequency area. They are National Park Police in Virginia near me. They are sometimes encrypted. They are NAC 4F9 in identification.