BOK Tower, formerly One Williams Center, is a skyscraper in downtown Tulsa, Oklahoma. At 203 m (667 ft) in height, the 52-story tower is the tallest building in any of the five "Plains States": Oklahoma, Kansas, Nebraska, North Dakota, and South Dakota, as well as the surrounding states of Missouri, Arkansas and New Mexico. It was built in 1975 and designed by Minoru Yamasaki & Associates, the same architect who designed the World Trade Center in New York. This structure is very similar to the WTC towers in appearance and construction. BOK Tower's lobby has marble walls and wall hangings which have a noted similarity to the decor in the former WTC.