William Clark

William Clark was central to the success of the Corps of Discovery expedition not only during the two years spent crossing the continent but also because he produced maps of the West long after his return. His three maps of the Western United States grew from sketches made during the expedition. He completed detailed maps during the winters of 1804 and 1805 in Fort Mandan and between 1805 and 1806 in Fort Clatsop, and finished a third map in St. Louis between 1809 and 1810. Clark had an extraordinary ability to place the landscapes he observed onto a one-dimensional map and a natural instinct for determining the course of rivers beyond his sight. His maps accurately showed the West as having multiple mountain ranges rather than the single range commonly believed at the time. His brother George Rogers Clark recommended him to Thomas Jefferson after declining Jefferson’s offer to lead the expedition, and Jefferson then recruited Meriwether Lewis. Lewis had served under Clark in the military, and the two became friends before Lewis invited him to join the Corps. Clark accepted, writing on July 18, 1803, that he would cheerfully join in an “official Carrector” and share the dangers, difficulties, and fatigues while anticipating the honors and rewards of the enterprise. An experienced woodsman, military commander, and surveyor with an outgoing and even temperament, Clark complemented Lewis’s skills and traits and helped provide strong shared leadership of the Corps.

Montana · United States