Great campsites. I visited *after* the 4th of July and it wasn't crowded at all, maybe 20% of the spaces were occupied? There are "walk in" and "drive up" spaces. Both were nice, but more mosquitos in the walk in sites though by far (bring a mosquito coil and DEET, leave the citronella at home). There are accessible versions of both sites and group sites (up to six people and two cars per site), all for $20. Quiet time is 10pm to 6am. No campfires but stoves are OK.
Between every 10ish sites is a vault toilet and a potable water spigot (no soap in the bathrooms). There's a single flush toilet at the entrance, there's a shower too but I wasn't brave enough to try it.
Nearest store was in Camp Connell, 5 mi down from the Bear Road/Hwy 4 turn off, they had everything you could need (🧊, meds, ⛽), including WiFi (no service or pay phones at camp).
Don't go swimming near the bridge - it's insanely dangerous. Follow the path past the rapids, past the lookout point and go through the underbrush into the ATV/ORV area and the path will lead you to an area you can wade or relax on some rocks. You *cannot* see the bottom of the river, it's very cold and very fast. Do not let a kid swim in this river and be careful not to slip on any rocks yourself.