 In 1804 , fifty years before the city of Omaha was founded , the Lewis and Clark Expedition first arrived via the Missouri River . The 1806 Fort Lisa and 1820 <unk> 's Trading Post were important fur trading outposts located in proximity to the river , along with earlier <unk> 's Post in Bellevue . The Engineer <unk> was built by Captain Stephen Watts <unk> 's Yellowstone Expedition in 1819 . The Expedition 's craft , the Western Engineer , was the first steamboat to successfully venture up the Missouri River to the Omaha @-@ Council Bluffs area . 
