There's cougar canyon, oriflame, san jacinto, borrego springs, ocotillo wells, all great places for camping, I grew up camping/backpacking/offroading in all of those places and absolutely LOVE it all!!! If you wanna see some truly amazing sights though, the "upper yosemite wilderness" is a little further than 4hrs north but well worth it, I spent 2 weeks backpacking up there and we saw 2 other people the entire 12 days on the trail, absolutely untouched and unpoisoned by humans. Also bishop is up there not as far, probably about exactly four hours north which is also amazing and less remote which may be safer with the kids, but bishop is full of lakes, streams, trails, ohv trails and pretty family friendly. Also big bear which is right in our backyard(San Diego) has some fantastic easy going trails that were mining roads but still have some of the structures from the aboveground equipment which were a ton of fun exploring, good-looking landcruiser!!!!