George Drouillard, the son of a Shawnee mother and French-Canadian father, was one of the most valued members of the Lewis and Clark Expedition. Meriwether Lewis wrote to Secretary of War Henry Dearborn that Drouillard was "a man of much merit; he has been peculiarly useful from his knowledge of the common (sign) language of gesticulation, and his uncommon skill as a hunter and woodsman." Discharged from the Corps of Discovery in October 1806, Drouillard partnered with St. Louis fur trader Manuel Lisa in 1807 to trap and trade on the upper Missouri. After returning to St. Louis, he related his explorations of the Bighorn region to William Clark, then Superintendent of Indian Affairs, who added the new information to his map of the West. Three years later, while employed by the St. Louis Missouri Fur Company, Drouillard was again at the headwaters of the Missouri River. As company men under Pierre Menard built a trading post between the Jefferson and Madison Rivers, trappers drew constant attention from the Blackfeet, who resented their presence. Frustrated by these constraints, Drouillard and a party from the post set out to trap along the upper Jefferson. After two days of successful trapping on his own, Drouillard and two others left the main camp on the third day. When they did not return, a search party found the mutilated bodies of all three men less than three miles from camp. Physical evidence indicated that Drouillard "made a most obstinate resistance" before being overwhelmed, and he was buried in an unmarked grave somewhere near the banks of the Jefferson River.