The Tacoma Eastern became known as the National Park branch of the Chicago, Milwaukee, St. Paul and Pacific Railroad. Between 1919 and 1980, the National Park branch would consistently be ranked the second most economically viable branch in the entire 1700-mile Milwaukee Road system. However, on March 15, 1980, the Milwaukee Road became the single largest railroad failure in American history. The former Tacoma Eastern portion of the railroad was conveyed to the Weyerhaeuser Corporation who used the line to move logs from Thurston and Lewis counties to a trans-loading facility at the Port of Tacoma for international export.