Jones Bar is a primitive river access in South Yuba River State Park, run by California State Parks out of its Sierra District. It sits on the south bank of the South Yuba River about 8 km northwest of downtown Nevada City, right where Rush Creek drops in from the south. The name goes back to a Gold Rush mining bar on this stretch, and the USGS still calls its long-running stream gauge "South Yuba River at Jones Bar." The swimming is in a short chain of green pools between granite boulders around the creek mouth, with no buildings or facilities at the water.

Most people walk in. Park at the Independence Trail lot on Highway 49, about a mile south of the Highway 49 bridge over the South Yuba, where there is a non-flush restroom. Head west a short distance on Independence Trail West, then take the Jones Bar Trail where it drops off to the right. State Parks rebuilt that trail on a new alignment after the 2020 Jones Fire, roughly 2,700 feet of single track, and it is steep the whole way down. The other way in is Jones Bar Road. From Highway 49 north of Nevada City, turn onto Newtown Road for about 3 miles, then right onto Jones Bar Road for about 4 miles. The last part is a steep, rough dirt road where four-wheel drive is recommended, and it ends at a small parking area near the river.

The pools are edged by granite boulders and bedrock, and depth changes a lot from one pool to the next and from month to month. The South Yuba runs cold and fast during spring snowmelt, and the park's own swimming guidance repeats state boating warnings about high, swift, cold water in big snow years. By midsummer the flow drops and the pools turn calm and much warmer. There are no lifeguards and no posted swim area. Check the Jones Bar gauge before you go; it measures the water you will be swimming in.

The park is open sunrise to sunset, and there is no parking at Jones Bar from 10 p.m. to 6 a.m. Jones Bar has no fee station. State Parks lists a $10 vehicle day-use fee for South Yuba River State Park, which is collected at the Bridgeport lots downstream. Dogs are allowed on the park's trails and shoreline here.

Independence Trail West is still closed past its junction with the Jones Bar Trail under a District Superintendent Order, because the Jones Fire burned its wooden flumes and bridges. Stay on the Jones Bar Trail, which is the open route to the river. The hillside above the bar is still recovering from that fire, so expect loose footing, little shade and real heat on the climb back out on summer afternoons. Bring all the drinking water you need, since there is none at the river. Some land near the road end is private, so respect posted signs.

Upstream, the Highway 49 crossing has more swimming spots along the river. Downstream at Bridgeport you'll find the restored covered bridge, a visitor center, gold panning demonstrations and the Buttermilk Bend Trail.