Fort Clatsop National Memorial was established in 1958 to commemorate the culmination and the 1805 to 1806 winter encampment of the Lewis and Clark Expedition on the Oregon coast. In 2004, Congress authorized the expansion of the Fort Clatsop National Memorial from 51 ha (125 acres) to 1295 ha (3,200 acres) and renamed the National Park Service unit to Lewis and Clark National Historical Park (LEWI). LEWI now encircles the ecologically significant Columbia River estuary.