Interactions between drainage flows and cold air pools were investigated with a three-dimensional numerical model. The model results were compared with tethered balloon measurements made at four sites running down a gentle slope at the foot of the Oquirrh Mountains in the Salt Lake Valley as part of the Vertical Transport and Mixing (VTMX) field campaign of October 2000. Simulations were carried out for several case studies having different synoptic conditions to examine the sensitivity of the drainage flow characteristics to large-scale winds. Two-dimensional simulations with exceptionally fine horizontal and vertical resolution were also carried out to investigate how drainage flow characteristics depend on cold air pool characteristics such as cold pool depth and stability. Results from the simulations were also used to evaluate the various assumptions in simple analytical and numerical drainage flow models.