Which forest service?
NC STATE OR US FOREST SERVICE?
USFS has a dispatch center in Asheville that covers quite a bit of NC via remote bases.
Go to the NC State wiki in the NC State part of this website to get NCFS frequencies.
Remember that NCFS repeater outputs are reversed from the usual practice of other states,
the 151.xxx frequencies are the repeater outputs, and the 159.xxx frequencies are the repeater inputs.
You want to program in the 151.xxx NCFS frequencies into your scanner.
For starters try:
NCFS District 1 151.475,
USFS Pisgah and Nantahale NF 168.725.
Also USFS law enforcement uses the US Park Service GSMNP LEO frequencies at times. 167.150 P25 mode.