Abstract: A stock watering device for preventing water therein from freezing during cold weather and for keeping the water therein cool during hot weather. The device includes an insulated tank, an insulated cover portion, a float valve for maintaining water within the tank at a predetermined level and a drinking well provided in the cover portion for providing drinking access. The drinking well includes a lower continuous edge extending below the predetermined level of water to form an effective seal between the interior of the insulated tank and the ambient weather conditions.