Final answer:
The Corps of Discovery traveled from St. Louis to the Pacific Ocean and back during their expedition from 1804 to 1806.
Step-by-step explanation:
The Corps of Discovery, led by Meriwether Lewis and William Clark, traveled from St. Louis to the Pacific Ocean and back during their expedition from 1804 to 1806. The journey took approximately two years. In five months, they would have traveled a significant distance, reaching landmarks such as the Bitterroot Mountains in Montana and eventually arriving at the Pacific Ocean in Oregon.