I haven't been to an RV Park up there, but I've stayed at several of the USFS campgrounds in that area. It's a great area.
If you are good with dry camping, a bit further north/east on Hwy 49 and you'll get to the Lakes Basin area. There are a bunch of campgrounds there that sit near one of the many lakes. Lots of fishing to be had. There are hiking trails that connect the lakes. Gold Lake is a gorgeous lake and has a nice trail around it. You can also get a great handmade milkshake at Bassetts Station. Many of the area's camphosts will rent a room at Bassetts Station for a night each week to get a good shower, eat at the restaurant, etc.
It's really a great area.
1975 American Clipper RV with Dodge 360 (photo in profile)
1998 American Clipper Fold n Roll Folding Trailer
Both born in Morgan Hill, CA to Irv Perch (Daddy of the Aristocrat trailers)