You can also get there by going west from Chimney park til it meets Lombard and then head north til it meets Marine Drive.
This is not fenced but it like 1000 acres it is very isolated. It is 100+ acres and has swimming. It also has picnic tables and restrooms. Lets meet in the second parking lot by the Lewis and Clark sign. There is a paved path to the beach. BRING WATER!
I haven't been to this park but I heard from those who have that it is really nice so I look forward to seeing everyone there. It should be hot by then so the dogs will appreciate the swim!