On the days of first come first serve what time do they open to be physically present to get a campground site? Is there a long line of traffic or people waiting?

They open the office at 7am! MOST WEEKDAYS (Monday-thursday) there isn't a big rush and USUALLY plenty of sites available. Friday and Saturday are a LONG shot for getting a spo, specially when the leaves are changing. If you are coming Friday or Saturday, you will want to be there NLT 7. Check out for people leaving is noon. And every day is 1st come 1st serve. I just spent 2 weeks there and it was full EVERY Friday and Saturday but VERY MUCH near empty Sunday-thursday

The day of week will likely have the biggest impact. We arrived at 4pm on a Wednesday and there were four parties ahead of us with 10 camp sites remaining. Thursday by 10a, all sites were occupied.