Folsom Lake State Recreation Area is a dam-formed reservoir on the American River, about 25 miles upstream from downtown Sacramento. It is a high popular area for many types of recreation, but for local climbers its draw includes endless short granite boulders, some of which are large enough to offer decent problems. Depending on the time of year and water level, some of these may spend time under water.
Since it is a state area, there is a charge for parking, and parts of it are only open during daylight hours. Camping is available in the park. Fees and hours for different entrances may change from time to time, so the best thing to do is to check the park website. www.parks.ca.gov/?page_id=500
Driving from interstates 80 or 50. Biking or walking in looks like a free option.