Cool off with a dip at South Yuba River State Park, which has popular swimming holes and hiking trails. It's near Bridgeport, which has the USA’s longest covered wooden bridge (temporarily closed for restoration at the time of research), a 30-minute drive northwest of Nevada City or Grass Valley.
This area has a growing network of trails, including the wheelchair-accessible Independence Trail, which starts from the south side of the South Yuba River bridge on Hwy 49 and continues for a couple of miles with canyon overlooks. June is the best time, when the rivers are rushing and the wildflowers are out.
The longest, single-span, wood-truss covered bridge in the USA, all 251ft of it, crosses the South Yuba River at Bridgeport (not to be confused with the Eastern Sierra town of the same name). It’s easy to spend a whole day hiking and swimming in this wild area, where crowds can be left behind with little effort. The Buttermilk Bend Trail skirts the South Yuba for 1.4 miles, offering river access and bountiful wildflowers around April.
Maps and park information are available from the state park headquarters in Bridgeport, or from the Tahoe National Forest Headquarters in Nevada City. The South Yuba River Park Association (www.southyubariverstatepark.org) is another great resource.