Best Big Rig Campground near Glacier National Park?

Is there a length limit at the National Park St Marys campground? I seem to recall a lot of the sites were pull-through, shaped like a curve, off central loop roads. It's not an RV park, there were no hook ups of any kind, at least not in 2013. There were "wooded" sites, and also some out in the open sites.

They gave a few very short generator-run windows, most folks obeyed.