Fort Clatsop was the encampment of the Lewis and Clark Expedition in the Oregon Country near the mouth of the Columbia River during the winter of 1805–1806. Located along the Lewis and Clark River at the north end of the Clatsop Plains approximately 5 miles (8.0 km) southwest of Astoria, the fort was the last encampment of the Corps of Discovery, before embarking on their return trip east to St. Louis.