Both Big and Little Cottonwood canyons, carved in the steep Wasatch mountains situated to the east of Salt Lake city, can significanlty affect vertical transport and mixing within the Salt Lake basin via their drainage flow. No quantitative understanding exists, however, as to how these canyon flows develop before interacting with the stable basin air. In order to study the stable boundary layers, the U.S. Department of Energy (DOE) Vertical Transport and Mixing (VTMX) Project launched a field experiment in the Salt Lake Valley in October 2000. Results of 15-hour (6 PM to 9 AM) simulations of 5 intensive observation periods (IOP s) (2 October, IOP # 1; 14 October, IOP # 5; 16 October, IOP # 6; 18 October, IOP # 7; 25 October, IOP # 10) will be discussed in the context of characterization of canyon drainage flow interaction with the basin air. Surface and upper-air mesonet station observations, profiler and sodar observations , and lidar data are being utilized in model validations. The Regional Atmospheric Modeling System (RAMS v4.3) is initialized and nudged with the NCEP reanalysis data.