Abstract: A recirculating livestock watering system provides drinking water at a temperature above the freezing point during the winter and below the ambient air temperature during the summer. The reservoir, having a bottom surface, a continuous side surface, and an upper rim surface, is disposed such that the bottom surface and a portion of the side surface lie underground. A water source is disposed underground at a depth below the frost line. A heating circuit includes a coil, a pump, an input valve, and a output valve. The coil has an inlet and an outlet and is placed below the frost line. The pump inlet is connected to the coil outlet and the pump outlet is connected to the coil inlet, forming a continuous enclosed path. The output valve releases water from the heating circuit into the reservoir upon demand and is disposed along the continuous enclosed path downstream from the coil outlet and upstream from the pump inlet.