Smallbore prone is big in PA. Most prone w/sling events welcome F-class shooters.
Might want to check with the state R&P association.
Best bet may be the "Coming Events" calendar published electronically by the NRA as part of its Shooting Sports USA e-zine.
All NRA sanctioned events are listed on the Coming Events calendar. It covers all shooting sports. You need to look for smallbore rifle, then Conventional Prone and Metric Prone. Not many specific F-class matches.
Direct link to Coming Events:
If that does not work open this link to the SSUSA mag and click on the image in the upper left
Be advised - this is very early in the season so not many matches are scheduled yet. You need to check the Coming Events calendar monthly as it is updated.