The Mid-Continent Tower is a 36-story skyscraper located at 401 South Boston Avenue in downtown Tulsa, Oklahoma. At 156 meters (513 ft) in height, it is the fourth-tallest building in Tulsa and fifth-tallest in Oklahoma. Faced with bright white terra cotta and crowned with a distinctive copper roof, it is one of the city's most recognizable buildings. The design is unique because the first 16-story structure was built in 1918. The top 20 stories comprise a separate structure, cantilevered over the first 66 years later. The architects of the addition matched the design of the original structure so carefully that the result is considered a single structure. It is included as a contributing structure in Tulsa's Oil Capital Historic District.