1271-1791 Explorations  of the Pacific Northwest coastline by explorers seeking the Northwest Passage

Captain George Vancouver   and his voyage along the Pacific Northwest coastline in 1792

Captain Robert Gray   discovered the Columbia River on May 11, 1792 while on a fur trading expedition
 on the Northwest Coast.

Lewis and Clark  left the mouth of the Missouri River at St. Louis on May 14, 1804. Their goal was the mouth of the Columbia River and the Pacific Ocean.