I've been picking up 168.475 with a P25 NAC of 4F9 for some time now but it sounds heavier than Park Rangers to me, I'll keep listening.
172.425 P25-167 FBI Bravo 5 ?
171.650 P25-293 ?
168.475 NAC 4F9 is in fact the North repeater for Delaware Water Gap Rangers and Park Operations.
171.650 NAC 293 is the Independance Hall National Historic Park (INHP) Rangers in Philly. They have a pretty strong signal and I frequently pick them up all the way up in Morris Co..