Just to tack on to what Dave wrote, I have camped in the Fouts Springs/Davis Flats areas several times. That is right in the center of the Stonyford Recreation Area, which is a few miles west of the little town of Stonyford. It is an excellent place for a ride weekend, with plenty of long hill climbs and technical single track, and is a major draw for people coming from the Bay Area. Races are held there too. I had friends who were enduro fanatics and I rode the Jackhammer Enduro up there with them 3 or 4 times.
On the flip side the area was closed for several years after the 2018 Mendocino Complex Fire and again this year due to heavy rains and snow. I don’t think you can really count on it being open for riding every year. Anyway, once the snow clears there are great single track trails close to Reno in the Tahoe and Plumas National Forests. Or I should say, if the snow clears this year.