In researching Olympia campground I also found American Heritage campground. Are these two different campgrounds that are located next to each other?
http://www.olympiacampground.com/They share the same email contact address and I sent them an email to see if American Heritage has electric sites available off season.
From the campground descriptions and looking at the pictures it sounds like Olympia campgrounds electric/hook up sites are row parking with the rigs right next to each other. However, the American Heritage campground sounds like there may be some electric sites in the wooded area.