In air quality and meteorological models, the bulk drag and turbulence enhancement due to cities is often parameterized through the roughness length (z0) and displacement height (d). These log-law parameters have traditionally been derived from meteorological measurements and building morphological characteristics (e.g., see Grimmond and Oke, 1999). In this poster presentation, we derive roughness length and displacement height for 3 US cities (Los Angeles, Phoenix, and Salt Lake City) using several common morphological formulae developed in the literature. The log-law parameters have been derived over 12 sq. km for Los Angeles, 16 sq. km for Phoenix, and 6.7 sq. km for Salt Lake City using commercially-available building databases. We correlate the computed roughness length and displacement height to underlying landuse type and compare our results to other studies in other cities. Maps will be produced that show the spatial variation of z0 and d for the three US cities. Limitations and advantages of using 3D building databases will be discussed.