Clueless what the temp might be this time of year (coolish?) There are things starting to happen at Columbia State Park Columbia California - Columbia State Historic Park - Gold Rush Country
Near Sonora. Not sure about camping, however, it is weird, not too many campsites along Hwy 49...and never more than one or two open in the "winter" months... go figure...
There is the 49er RV Ranch (never been there, however) you'd need to contact them to see if they are open during this season: 23223 Italian Bar Road, Columbia, CA (209) 532-4978. The town and State Park are great fun, however! Shouldn't be crowded at this time of year.
Mrs. NorCal Bambi Traveling in S Tardis ~ from the Great State of Jefferson
My blogs: Yreka History
Siskiyou County Camping
49ER RV Ranch