Gear from a water-powered sawmill

On my way home I stopped at a little beach in San de Fuca on Penn Cove. I grew up about a mile from there and, oddly enough, I have never stopped there before. It is even more odd that it is the site of an old saw mill from over a hundred years ago. It was powered by the tide. The tide would rise and fill a large bay with one narrow inlet. I assume it was dammed and would turn a water wheel to power the mill. Talk about renewable energy. What made us stop from embracing that kind of technology?
The thing that makes it odd that I never stopped there before and, in fact, never knew that it had been a sawmill was that my dad had a sawmill just two miles from there. He built it on 80 acres of forest land in the late '40s, just after WWII. It was a rotary blade of about three and a half feet in diameter. He knew all of the old timers in the area (because he was one of them), but he never passed on this bit of info. I learned it from a local history book.
I like gears and old iron. I wasn't expecting to find this big one sitting in the sand. That was a plus.