I've got to be blunt, I really don't know of Lake Silver is a natural pond or man made. Let's say if it is natural, it has been "improved" upon many times over the years. Going back to my first visit in 1970, Lake Silver was there. It was completely isolated in the woods back then. The train followed the same track it does today around the lake. Prior to the opening of the "Deepwoods" in 1977, there was a feature on the lake of a man fishing in a boat. The train conductor had some patter about that was a private lake, and why was that guy using the condutor's new boat. Then the conductor fired a round at the man in the boat, and the figure of the man swung around and shook his fist at the conductor. It got a pretty good laugh. When the diving bell was added as part of the new Deepwoods area, the Eli Tolt submersible was on one side of the lake, and the fake diving bell submersible was adjacent to the diving bell building. The man in the boat was removed so as to not conflict with the diving bell story line. In 1984, when the Greedy Brothers Boat Excursion was added to the Lake Silver area (for just that one summer) the big wooden structure used as a target for the water cannons at the kids playground was built. The structure was part of the Greedy Brothers attraction first. People would load into boats at Greedy Brothers and would follow a course in the lake in a search for treasure. Water geysers and fountains would splash people in the boats as it worked through the course. It was about this time that the kids Shantytown playground was added, too. As attractions came and went, the Lake Silver area was developed more and more. So things were added and taken out of the lake over the years. At least part of the lake has a concrete lining, and you will see this if you visit in winter when they draw down the lake level for the winter months. I believe that is done so they can do maintainance on structures around the lake. ZEPHON says the center of the lake is the deepest, at about 15 to 20 feet. I can tell you the water level around the Lost River structure (formerly diving bell building) is only about waste deep on a grown man. I know this because on my last day working at the diving bell in 1983 my fellow Juniors pulled a prank on me and threw me in the lake! I landed ten to fifteen feet away from the wharf at the diving bell, summersaulting as I was tossed, and landed on my feet. Memories! Anyhow, that is a short history of Lake Silver as I know it. Maybe ZEPHON or another current citizen is in the know about if the lake is real or man made. I know at one time somebody jokingly told me that the lake was the original sewage pond for the park, but I think looking back all these years later on the source, they were pulling my leg.