Whoa! This place is beautiful. The whole town (new to me), the American River, and the Raft California property specifically.
So, camping at Raft California, you have several options depending on your preference. For larger groups, they have an entire private section along the river where you're left to yourself, away from everyone. That area has a kitchen setup, banquet tables, etc... but still feels like camping.
If you brought a tent, there's also plenty of room to pitch one in the more common area. My friend and I came through town on a longer road trip, so we opted for the nicer setup in one of their canvas tents - more of a "glamp" setup, to keep everything extra easy. Inside those are 4 cots, so plenty of room for most families as well.
Raft California is also, and most importantly a raft guide company. As such, there are a few people coming and going, employees and tours. That also means they have lots of activities on site, clean bathrooms and showers, picnic tables, etc... basically most of the conveniences of home! On the other hand, they're also do raft tours! I'd never gone down a river outside of NC, so I had to sign up. So fun! The guides are super knowledgeable (gave us information on what it's like from their end), and entertaining. They clearly seem like they're having a great time. The river was incredible, a few times surprising me with sizable waves and drops. Absolutely loved it! I definitely plan on coming back!