Serrano Campground at Big Bear California

Thanks much for the info, I could not find the specifics you found!

Recreation.gov says "The campground offers more than a hundred sites for tent and RV camping. A couple dozen sites provide full utility hookups for RVs and a dump station is located within the campground. "

I had to go all the way into making a pretend reservation before I could find out that these hookups are electric, water, sewer. 28 sites.

It is good to check such details, because sometimes "hookups" does not include sewer.