Although this seems to be a significant mid-century addition from 1958-60, there is not a lot of information available on its construction. It is located on the corner of Hawk and Elk Streets behind the original main behemoth building by Palmer & Hornbostel (1908-12) on Washington Avenue (pictured at bottom). Unlike some of the more bombastic buildings at Empire State Plaza, this addition is restrained and corporate, with white stone cladding and metal window surrounds. The base is clad in grey stone with a projecting two-story entrance bay.
Once the addition was completed, the New York State Museum took over the entire top floor of the original building until its removal to the new museum on the other side of Empire State Plaza in the 1970s.