I just spent the weekend following the 4th of July up near Nevada City. It got over 90 degrees during the day, so we headed to the river. Although lots of people had similar ideas, I was with a local who directed us to this spot and we had it to ourselves. You park near the bridge and hike along the ridge above the river (about 10 minutes - wish I'd had some tennies instead of just flip flops), but it was well worth it. The water was fantastic and the scenery was beautiful. The rocks in the canyon are unusually rounded/smooth.