We spent two nights here with in our travel trailer while visiting Mammoth Lakes. I made the reservations online. It was not clear on the website that a 'standard' RV site only has water and electric and cable hookups- not that we needed the TV, but we didn't have a sewer connection and that was a pain! Fortunately, we were right near the restrooms/showers/laundry room, so it worked out OK.
The prettiest part of the park with lots of huge trees was pretty full- we stayed on the other side, which was OK. Not very many people there at all on a Sunday night! We didn't hear too much road noise at night. We parked on asphalt. We had a fire ring and a picnic table, water and electric for $52 (with all the taxes) each night. They told us that the Fire Service had decided to allow fires at all the sites, which was great. I can't imagine camping without a fire!
There is a nice indoor swimming pool/spa at the park that is open until 9PM. The office where you check in and check out also has a little store with all the camping supplies/emergency RV supplies you need. They also have firewood for $6 a bundle.
The RV park is also on the free shuttle line that can get you pretty much everywhere in town.
The only complaint is that the Wi-Fi was very spotty. They did tell us that as more people came into the park, the wi-fi would slow down. We are huge hockey fans, and we wanted to watch game 7 of the LA Kings-Chicago Blackhawks Western Conference Finals on our ipad. We had a difficult time keeping a connection, but eventually we were able to at least hear most of the game on livestream.
We enjoyed our stay and will be back!