Fort Clatsop, Oregon, to Camp Chopunnish, Idaho March 23-June 9, 1806
On March 23, 1806, the Corps of Discovery left Fort Clatsop, their winter quarters on the Pacific Coast, and started back up the Columbia River on their long return journey to the United States. It was now nearly two years since they had left St. Louis bound west; if they could get across the Rocky Mountains by the Lolo Trail early enough, they could descend the Missouri River before it froze and reach their starting point in this same year. They were now largely retracing a route they had already followed and so did not bother with the detailed courses and distances of the outbound journey, but their journals were still filled with the incidents of the voyage and descriptions of the country and its people.
There was still room for new discoveries; on the way down the Columbia they had missed the mouth of the Willamette River, concealed behind islands. They encamped for a week on the north side of the Columbia to hunt and take astronomical observations, while Clark made a quick exploration a few miles up the new stream. The captains called it the Multnomah after the Indian name and regarded it as coming from much deeper in the continent than was really the case. On April 6 the party was again on its way.
They were nearly two weeks getting upriver past the Cascades and the Celilo Falls. To the wearisome labor of portaging was added the aggravation of bad relations with many of the Indians in the vicinity. The natives demanded high prices for any food they sold, and some of them could not resist stealing. The captains' patience was at low ebb and they threatened violence if stolen goods were not returned. When some Indians made off with Lewis's dog Seaman, Lewis sent a party of men to recover his friend and companion, with orders to shoot if necessary. Fortunately, no one was killed and Seaman was returned to the Corps.