Columbia Island is an island located in the Potomac River in Washington, D.C., in the United States. It formed naturally as an extension of Analostan Island in the latter part of the 1800s, and over time erosion and flooding severed it from Analostan. The U.S. federal government deposited material dredged from the Potomac River on the island between 1911 and 1922, and again from 1925 to 1927. The island was also reshaped by the government at this time. It received the name "Columbia Island" about 1918. In 1968, the island was renamed Lady Bird Johnson Park. Located within the park are the Lyndon Baines Johnson Memorial Grove, Navy – Merchant Marine Memorial, and the Columbia Island Marina.