Citywide constructs such as "West Side" or "South Side" are spatial codes that result from more than the informal conversations of city residents. This article shows how elementary school educators in one U.S. metropolitan school district participated in the production of a local knowledge of the East Side and West Side space and individual. It demonstrates how educators used these codes to name race and class, as well as to obscure the codes' meanings. The article maps the convergence of institutional technologies and local educational knowledge whereby this knowledge resisted change and buttressed the citywide East Side-West Side relations and knowledge. The disjunctures in this knowledge base are also identified, as educators attempted to produce a knowledge of a third space that they termed "Central City." (Contains 11 notes.)