If you find yourself in Ulster County looking for a lake to swim that’s not Minnewaska, here’s the spot: Onteora Lake, a few miles west of Kingston. I met three NYOW swimmers here one Saturday morning at the end of a short June vacation in the area, and another swimmer happened to be already in the water when we started. Other than us human vessels, human-powered fishing boats and slow-moving electric ones were the only other craft in the lake. The fishers mostly hugged the shore, leaving the middle clear for swimming. We stuck together and switched off between easy swimming and upping the effort for set numbers of strokes. Phew.
This skinny, kilometer-long lake must have heated up due to recent warm temps; it’s less than 20 feet deep. We could see flowers along the edges and some interesting bird life. Part of Bluestone Wild Forest (in the Catskills), it felt quite remote except for the sounds of the the nearby highway at the south end. It was also quite silty both to taste and in my bathing suit, turning my post-swim shower briefly into a mudbath.
Should any nonswimming companions join you, they can hike or bike on trails around the lake and beyond. Parking is easy in a lot off the highway or farther in the same access road right by the lake. We left our things by a picnic table and no one paid them any mind. There’s no schedule or lifeguard, meaning you can come and go as you please — a particularly important feature during this darn pandemic.
40 Pools 
I didn’t see this post last summer but am in Woodstock for a couple of months and this is a great distance-swim alternative to driving the 45 minutes to Minnewaska (whose MDSA I joined last week). Saw a blue heron fly overhead.
Excellent! I actually got to swim in Minnewaska once this past week and it was gorgeous. Mountain laurel in full bloom. Tons more parking than there used to be, yet still plenty of room in the water. 🙂