EDIT 9/3: We were able to reserve the Marzolf Shelter House. We will be in our usual location this year.
We are just a little under two weeks out from the event. I took a recon trip out to HLK on Sunday to review a couple of the picnic areas the park offers, since both the Marzolf and North Shelter houses are booked for that Saturday. I would welcome any suggestions based on my observations below. I have a map to reference the sites I am referring to available here: https://k8bxq.org/sites/k8bxq.org/files/2021-08/hlk.jpg
1. The picnic area on the south side of the lake between Marzolf and the boat launch has adequate parking, a lot of picnic tables, and grills as well. There are plenty of trees to string antennas also. We would probably want a couple of 10x10 easy-ups to shelter from the sun and possibly any rain. The downside is that there is no restroom/outhouse within convenient walking distance.