Follow the dirt road for about a mile. It ends at the parking area. Enter the woods by way of a well-trod path, and follow it around the edge of the lake. Some signs posted by users may display their rules of acceptable behavior. Once you see that, you know you are there.
Parking is free, and porta-toilets are available at the parking lot.
You must get dressed to use them, however. Nudity in the main picnic area is likely to be cause for local police to be called. Staying to the unofficial area that naturists have used for years is important. All rights reserved.