There's a few. You can check the internet for some popular camping clubs like Woodalls, Trailer Life and similar and they can list some. There are a bunch of CGs around Bass Lake, another in Oakhurst nearby and one in Wawona on the way to Yosemite.
These all fill up fast but if you are looking for several months from now, you can try, but again, they fill up fast.
I'll be in Yosemite Valley the week before Memorial Day and a friend I'm going with reserved about 2 months ago.