I traveled here during the week in late August -- the weekend after schools in Idaho started back up. The campground was well tended and it was easy to score a site _ though it being midweek might be the difference. Nice and quiet. Large sites suitable for tenting or RVs. Sites are along the river, which makes for relaxing background noise.
Having two vault toilets is a nice bit of luxury.
Not surprisingly, but FYI, that there is no cell service here. However, if you really need to be connected, the Hells Canyon Outlook is about 8 miles away and has 4G/LTE service.