Alternative Names:  National Bank of Tulsa Building, Exchange National Bank Building
Address: 300-320 South Boston Avenue
Height: 400.00 feet
Floors: 22
Constructed: 1928

The 320 South Boston building is one of the most iconic structures in Oklahoma. Situated on the west side of Boston Avenue, the layout of the 400 feet tall brick building covers a full city block between Third and Fourth Streets.

The structure was originally built in 1917 as a 10-story office, which housed the Exchange National Bank of Tulsa. In the late 1920s, amid a building boom downtown, the building was expanded, and a 22-story central tower was added to the south side in 1927. A 10-story building, which is identical to the original structure, was also added on the south side. The original structure is now known simply as the building’s north wing.

In 1933, Exchange National Bank renamed itself as the National Bank of Tulsa. The building’s name was changed to reflect the corporate rebranding, and the building was renamed from the Exchange National Bank of Tulsa Building to the the National Bank of Tulsa Building.

In 1949, KOTV chose the roof of the building as the site of its first transmitter. The first live television pictures ever seen by residents of the region were received by the transmitter until 1954, when it was moved to a higher elevation.

During the 1950s and 1960s, the building was used as a weather warning system for Tulsa, according to “The Tulsa World.” Lights atop the building kept people informed of severe weather, with flashing red lights signaling thunderstorms and green lights meaning clear weather.

According to the paper, the building also once moored a U.S. Navy zeppelin:

“Probably the most unique characteristic of the building is its apex, which was designed to be a zeppelin mooring. During the 1930s, at least one Navy zeppelin briefly moored there. In fact, the Tulsa Historical Society has a large photograph showing people hanging over the building’s uppermost railings to grab ahold of the lines hanging down from the giant airship.”

In 1975, the National Bank of Tulsa again changed its name, this time to Bank of Oklahoma (BOK), and soon moved across the street to the then newly completed BOK Tower, which opened in 1977.

Since 1977, the property as been known simply as the 320 South Boston building, and houses a variety of tenants, including a number of law firms and advertising agencies.

TRIVIA: During the construction of the KOTV transmitter in 1949, a wrench was dropped from the roof of the building, striking and killing a woman on the street below.