I've gone to Salmon la Sac (aka Fish Bag) almost every year for the past 10 years. It is my favorite! The campground itself is light on amenities so it's good if you like to rough it, but the beauty and quietness make up for it spades.
The park is beautiful, but not in a good way. Instead of feeling like I was in nature I felt like I was in a manicured neighborhood park. The sounds of the neighborhood streets took me right out of feeling like I was camping.
The sites are super tiny and the tent platforms are equally so. The place seemed much better suited to glamping than camping.
The campground itself was a lovely family friendly campground with easy access to toilets and water with decent privacy, but the sites closest to highway 410 (sites 1-24) are a noisy from traffic. If traffic doesn't bother you then don't worry about it, but I had a hard time sleeping in the peace of nature with traffic racing by.