I-5 north of Redding to Oasis Road. Follow Oasis to Bear Mountain to the village of Jones Valley.
Locals start at the campground and ride the loop counterclockwise.
Tricky to find the singletrack south of the paved road, but worth it. Two short climbs of a quarter mile each, and summer swimming in Lake Shasta. Nice free map from the Forest Service. Lots of runners and equestrians, so be cool. Ride west out of the boat ramp parking lot for a counterclockwise loop.