There is camping all along the mout of the yuba and feather rivers. The only con is that there are a lot of metal health plagued homeless people in the area making camping peacefully, difficult.
Camping is not allowed in the park but as was said in the previous response a hike-in site is available off the Point Defiance trail.
Not sure about the area near the bridage or other side of highway but if you take the path on the bridge side a couple miles, it takes you to the north end of englebright lake at the campground at the mouth of the two forks of the yuba. Very cool sites, big general area. One of our favorite sites!
You'll see many camping but whether it's legal or not or safe or not is a different issue. There is a hike in a mile or so towards Englebright lake West of the old bridge on North side that leads to I believe what named Point Defiance campground.
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