Review: This is a very nice RV park that even has an RV washing station.  Sites are large and level on gravel with grass in between, and some small trees.

The main challenge with this park is it is right next to I-5 and train tracks, so we heard a LOT of train whistles both during the day and at night (and you can feel the ground shaking when the train goes by).

You can walk to the Toutle River from the campground (about 1 mile round trip), and they have a lot of nice facilities in the park itself (e.g., pool, hot tub, sauna, horseshoes).
If you can tolerate the train noise, we think this is a very nice park, and we would stay here again if we wanted to visit Mt. St. Helens.