It was our first visit to Mt St Helens area and it was amazing.  April is not peak season so the campground was pretty quiet and the weather was a bit chilly.  We booked a spot right next to the lake.  The people that run Streeter's are super nice and helpful.  The little store / cafe is great.  We also went into Castle Rock for dinner one night at the Oasis and found the people there to be super friendly as well.