Lower Wolfjaw Mountain stands within the watershed of the East Branch of the Ausable River, which drains into Lake Champlain, thence into Canada's Richelieu River, the Saint Lawrence River, and into the Gulf of Saint Lawrence. The east and southeast sides of Lower Wolfjaw Mtn. drain into Wedge Brook, thence into the East Branch of the Ausable River. The west side of Lower Wolfjaw Mountain drains into Wolfjaw Brook, thence into Johns Brook and the East Branch. The north side of Lower Wolfjaw drains into Bennies Brook, thence into Johns Brook. The northeast end of Lower Wolfjaw drains into Rock Cut Brook, thence into Johns Brook.