We will present results from a photochemical box model initialized with observations taken from the 62nd floor of the Williams Tower in the Uptown Galleria area of western Houston. The resulting analysis will focus on the localized rate and efficiency of ozone production in air that had recently passed over the major NOx/VOC sources of greater Houston. The measurements made at this site were well above localized surface sources that often complicate the interpretation of observations from ground-level stations, providing an integrated measure of the chemical mix of this area.