I was at the park Saturday through Sunday (June 25th-27th). Mayflies crawling all over the park. I don't know if this is normal ,but a lady from the park. Some sort of manager told us they were Mayflies and that they show up when the lake is healthy. How long do they stay? They are very interesting. Were they there only this weekend in such mass amounts? Poor things don't know when to get out of the way of a speeding rollercoaster train.