There is two ways you can come from: From Porterville, Drive 34 miles east on highway 190 to Camp Nelson. Continue on about 15 miles southeast on highway 190 to the entrance road.
Forest Road 21S07.
Or from Kernville (Lake Isabella) take the 178 to the 155 take the 155 around the lake to the 495. Take 459 to Mnt. HW 99. Follow that all the way to M50. M50 to M90 stay on that past Trail Of 100 Giants Trail (Long Meadow Grove) about 17miles to Upper Peppermint ( Forest Route 21S07) if you go past Peppermint Creek you've past the road
There is brown sign that says Peppermint campground, and a dirt turn off.
That's the best I can do and it took me an hour, I didn't save the GPS because we've been going there for years. Sorry.