A month long meteorological field campaign sponsored by the Department of Energy’s Environmental Meteorology Program was conducted in the Salt Lake Valley during October 2000 to study vertical transport and mixing (VTMX) processes. Measurements made during the 2000 VTMX field campaign focused on nocturnal stable periods and morning and evening transition periods within the urban valley. A wide range of remote sensing and in situ measurements were made including those from surface meteorological stations, temperature data loggers, sonic anemometers, radiosondes, radar wind profilers, sodars, and lidars. Thermally-driven circulations, including nocturnal down-valley, canyon, and slope flows along the Wasatch Mountains, were regularly observed when the synoptic forcing was weak. A mesoscale model with a 550 m horizontal grid spacing was used to simulate the boundary layer evolution and circulations in the region for several of the intensive observation periods. The model qualitatively reproduced the converging down-valley and canyon flows as measured by surface stations, radiosondes, radar wind profilers, and the Dopper lidar. The model and perfluorocarbon tracer observations are used to describe how the mean vertical velocities and turbulence produced by the interaction of the down-valley and canyon flows transport material released from the surface above the surface stable layer.