In which direction did the Corps of Discovery travel as they moved from St. Louis to the Oregon Coast?

Lewis and Clark took part in the Corps of Discovery journey.

The route of Lewis and Clark's expedition took them up the Missouri River to its headwaters. After which they then went on to the Pacific Ocean through the Columbia River route.

It is believed that they followed this route because of their purported transcontinental journey of Moncacht-Apé by the same route about a century before.