The Lighthouse

There's a lighthouse in the state of Michigan to the north is Lake Huron and to the south is lake Michigan. It stands in a unique spot. You see when it rains, if a drop of water lands on the north side of the lighthouse. It'll roll-off, fall to the ground, flow into Lake Huron, and eventually end up in the north Atlantic ocean. However, if the rain falls on the south side of the lighthouse. It'll roll-off, fall to the ground, flow into Lake Michigan, and eventually end up in the Gulf of Mexico. Often only a slight breeze is all takes to determine a water droplet's destiny.