the area of watertown was inhabited for thousands of years before the arrival of settlers from england. the tribes of the pequossette and the nonantum, had settlements on what is now called the charles river. the pequossette built a fishing to trap herring. this was at the site of the current watertown dam. every year the alewife and blueback herring swim upstream from their adult home in the sea. this is to spawn in the fresh water where they came from.