We stayed at Bomoseen State Park on a busy weekend in the squirrel lean-to, which was right on the water. It was during the COVID-19 pandemic, and we are happy to report that everyone wore masks in public spaces (restrooms), and that there was plenty of room for social distancing.
Because of the pandemic, the snack bar at the beach was closed, and there were no boat rentals available or picnic tables in the day-use area. The beach was lovely - sandy and perfect for swimming. It was fun to watch the boats coming and going too.
Aside from spending lots of time in the water, here are a few more activities I'd recommend -
Walk the Slate History Trail and the Bomoseen Loop Trail. Walk over to Glen Lake, which is a very quiet lake with a pretty trail alongside it. This was great for us because we brought our dogs and they could swim in Glen Lake without disturbing others with their antics, plus they're not allowed at the Lake Bomoseen Beach.
If you have time for a little side trip, I highly recommend heading over to Taconic Mountains Ramble State Park for a hike. The views were incredible, and there's even a Japanese Garden where you can relax and have a picnic. Hubbardton Battlefield is cool too.