I haven't stayed in the Chehalis park, but I have stayed at Toutle River RV resort a few times. It is off exit 52. There is highway noise and the other side of the campground has train tracks so you have trains that go by and blow their horns. Aside from those two thing the campground is really nice. Full hookups, large sites, pool, hot tub, sauna, disc golf, playgrounds, river access, and little store to pickup things you may need.
EDIT: After posting I realized that my sig pic was actually taken at the the Toutle river rv resort.