Thomas Jefferson had dreamed of charting the western territories, 
even before he purchased Louisiana from the French in1803. He 
entrusted the first expedition to Meriwether Lewis, and private 
secretary. Lewis contacted his old army friend, William Clark, to join  
him. The Lewis and Clark Expedition consisted of about forty men 
and on woman, Sacagawea, and the total cost of the journey was 
nearly $39,000. The explorers left St. Louis in May 1804, traveling 
along the Missouri River and then through the Northwest until they 
reached the mouth of the Columbia River and the Pacific Ocean. They 
returned to their starting point in September 1806.  Shown here are 
Lewis and Clark attempting to communicate with the Indians. This 
expedition opened the way for westward expansion, changing 
forever the way of life for the Indian tribes throughout the region.