A nice little (120 spaces or so) full hookup (30 and 50 amp) campground.  We paid $289 for 5 nights. Clean, well maintained and full of families.  Very close to downtown and Anza-Borrego Visitor Center.  Spaces are good size, no problems fitting our 30' toy hauler towed by F250, and the park is well laid out and easy to drive. Checkin was fast and easy.  There are full time residents, but they are in a different section.  We used it as a base for hiking and off-roading at Octotillo Wells (both recommended,but bring as much water as you  can carry). The property has an old west theme, and there is also a hotel , laundromat and restaurant. If you have never visited this part of California, be advised that the wind here can be VERY intense, especially at night.  Also note that Borrego Springs is a dark sky community, so please be respectful and remember to look up and enjoy the stars.

We decided to extend our Borrego Springs trip (first time here) by one night and try a little boondocking at Peg Leg Smith Historical Marker (yes, there is actually a marker).  We did not arrive until well after dark, so the parking was a little challenging (F250 pulling a 30' Toy Hauler) but overall not bad at all. 

The lot is fairly uneven (for free-99, what do you expect?) but was a great little spot (the uneveness of the lot can be easily dealt with by leveling ).  We were one of 7 rigs there for the night, and there was one group of tent campers.  The only real issue was the wind, which is very common for the desert - about 2 hours after sunset, it really started to howl an rocked the trailer until about 8am the next day.

We were able to find it in the dark without too much drama.  We entered from the Salton City side - exited Highway 86 at  Sunrise Road, then Borrego Springs Road for 22 miles or so.