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 mi (8 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.