Alpine Geophysics staff has direct, hands-on experience in the use of all of the photochemical models identified by the EPA in it's recent 8-hr modeling guidance as well as a number of emerging PM2.5 grid-based models. The breadth of experience of Alpine's staff in applications with the full range of contemporary photochemical models underscores the firm's competence and proficiency in regulatory applications of state-of-science models. AG is not invested in any particular air quality model, and has demonstrated proficiency in applying all of the meteorological and ozone models identified in the EPA's 8-hr guidance. Thus, we are able to select an appropriate combination of current state-of-science emissions (EMS-95, SMOKE), meteorological (RAMS, MM5), and air quality models (CAMx, MAQSIP, Models-3/CMAQ, URM, UAMV) for use in a given application.