We just stayed here for the first time. We were at Boyer Park & Marina, a KOA,  Sept. 1-5, 2024.  While the campground was full when we pulled in on Sunday, it was almost empty when we woke up Labor Day morning. Even when full, everything was pretty quiet. The beach and walking paths are very nice and close by no matter which spot you're in.  Just below the Lower Granite Dam, it's an easy three mile round trip walk on a paved Snake River Trail. I do not recommend making that journey when it's 83 degrees and getting warmer. UGH

The store is great with many clothing options and more. Mike and Monica who run the place are so nice and very helpful. Apparently we really missed out by not taking advantage of the grill and ordering a Smash Burger, which will even be delivered to your campsite. 
We will definitely be back.