Idyllwild gravel/easy dirt?
 

Have a camping trip planned for Stone Creek Campground up in Idyllwild in August. I'll have my gravel bike which I'll ride on anything, and my teenage son is pretty solid on his hardtail, but I'll also have in tow a couple very inexperienced riders, on budget mtb's. Any suggestions for easy-ish dirt around there? Fireroads, mellow singletrack, etc?