Often these days, vault toilets are composting. In a campground, they are often the task of the host to clean (in return for a camp spot with electricity, etc.), and they can be super clean! This also minimizes fecal runoff going to nearby bodies of water, incidentally. People need to know how to use them correctly, however..... Instrux next to the toilet.
I would guess with a party this large, the guys were using the woods (not a bad thing for urine, because it disperses the liquid; it's also the recommended location for guys to urinate in the wilderness for this reason; also dry poop composts better). The few toilets that would be available (certainly not enough toilets for a huge crowd!) would be used by women and poopers, I would speculate.
With a party this large, I would think the toilet area was busy, but mostly women.
End of my bit on vault toilets, but this might give you an idea about people-flow and dynamic in the campground.